Blur

This achievement requires you to,
Complete 1 challenge pack to 100%
Complete 3 challenge packs to 50%
Complete the ultimate comback challenge
Complete the retribution challenge
First for completing 1 challenge pack to 100% i would recommend doing Drivers Ed, this is the first one you unlock and also the easiest, it only requires you to get accumulative objectives which you can check in your challenge menu from multiplayer, you will get these while you are going for rank 50, if you don't plan on going to rank 50 you could boost these but its not worth it.
For completing 3 challenge packs to 50% i recommend doing the Drivers Ed, Demolition and Daily, Demolition will take longer to complete than Drivers Ed, first of all because you have to be a high enough rank, and because it takes a little bit more skill. By the time you complete Drivers Ed you will have demolition unlocked and you can start working on that, remember you only need 50% of it done. The last easiest one is the Daily challenges (you should have this unlocked after you finish 50% of the demolition challenges or earlier), this is easily done to 50% because one of the challenges requires you to complete 20 races and by the time you do that you will have at least 7 of the other challenges done (which gets you 50%). If you don't keep playing until you do because they are quite simple to get (they reset everyday at midnight so you can keep getting fans off of them every day which is good for getting to level 50.)
Now on to the specific challenges, the retribution challenge is located in Demolition, it requires you to get 5 revenge attacks during a single ranked event (any event will do). The easiest method to do this is go into a motor mash and play it. You get a revenge attack almost everytime you hit someone, but if you don't know how to get one you first need to be hit by another player then you need to hit them back.
The final challenge and by far the hardest and longest is ultimate comback. This challenge is under the Ace challenges (which you don't unlock until level 30), you may or may not have this unlocked by the time your done all the other challenges, if you don't then you will just have to wait until you reach that level. If you do then to get this challenge it requires you to go from first place (You cannot start the race in first) to last place and then go on to win the race. This does not have to be on the last lap or anything, as long as you are in first at anytime and last at anytime and win you will get this. The easiest method is to get a small group of people together in your party and join a gametype with not many people (hardcore, community, or world tour are usually empty) and just boost it. If you play all the way to 50 however, you can get this by starting a race in first place then picking up a nitro or two and wait until you are in last (the less amount of people the easier) then when you are in last nitro back to first (best done near the start if possible and on a long race, A class races are usually 3-4 laps which gives you plenty of time) once you finish in first the challenge will unlock.
Remember the daily challenges reset everyday so make sure to have the daily challenges done on that day.

There is a glitch concerning Specialist which will help you complete it to 50% easily. Simply go into a Motor Mash session and use only whatever is specified (nitro, mine, bolts, etc.) You do NOT need to win.

Credit goes to Radioactive Microbe of xbox360achievements.org

My hint concentrates solely on perhaps the hardest part of this achievement - the Ultimate Comeback.

Even now, despite the game's age, this can be extremely difficult to get legit as people hold onto their Level 50s, meaning you need to be a decent level, have a good car and a whole lot of skill and luck to even have a chance of getting this part of the achievement.

However, there is a bit of a way to boost it, and to also gain for yourself a win in Hardcore Racing towards the All-Rounder achievement.

Firstly, make sure you are level 30 and above and have the Ultimate Comeback challenge available to get (it unlocks at level 30).

Next step is to grab 3 friends and get ready for a hardcore match. The minimum number of people required for a hardcore race is 4.

The crucial step is this - try to have one of your friends/boosting partners come from a part of the world where either:
a - the boosting session is at a time that is late at night or early in the morning (reducing the number of people in that part of the world that will be online playing Blur).
b - the country simply has a smaller population of people - thus reducing the number of people there that will be playing Blur.

This point is important because the next step is for that person to set their matchmaking preferences (press X when you are looking through the multiplayer game modes) to "Local Region Only".

What this does is increases the chances that this booster has control of their own hardcore racing lobby.

Blur's matchmaking works in a way that sees a new lobby created if the person looking for a race has "Local Region Only" set as a preference, and there are no other people from that country online and looking for that particular race mode.

Not only that, but once that player/booster has control of their own lobby, they can easily invite friends or their party (the second option being preferred) into the lobby immediately (by pressing the X or Y button) so that the 40 second countdown clock before the race starts.

Once you are at this stage, it comes down to luck as to whether someone else outside of your group joins the lobby. If so, simply exit and set up a new lobby and invite your party in.

But by following the steps above, you have increased dramatically the chances you will have your own lobby and will be able to set up races in order for participants to get the Ultimate Comeback part of this achievement (as well as win a hardcore race for the All Rounder achievement)

In getting this achievement myself I was in a party with 3 other people from the other side of the world - where it was daytime - while it was very early morning my time.

No-one in my neck of the woods was online and wanting to do hardcore racing so I was easily able to set up lobbies.

From there, we only had one time where someone else got into the lobby before our race started. The other times we raced we were left in peace and were able to get this achievement for a few people rather quickly.

Best of luck, and hope this helps.

In order to get this achievement, you have to complete 4 requirements in the online multiplayer part of the game.

Requirement 1: Complete 1 Challenge Pack To 100%

This requires you to complete all of the Challenges in one Pack. All of them apart from the "Ace Challenge Pack" have 16 separate Challenges (Ace has 15). Therefore all 16 Challenges must be completed for this requirement to be complete.

Requirement 2: Complete 3 Challenge Packs To 50% Or Above

You need to complete 3 Challenge Packs with at least 50%+ of the challenges done. If you go for Requirement 1, you will gain progress already towards 1/3 for this requirement. So in reality you only need to focus on 2 of the Challenges towards 50% or above. Apart from the "Ace Challenge Pack", all of the Challenge Packs have 16 separate Challenges (Ace has 15). So you need to finish at least 8+ Challenges for the game to register a completion towards this Requirement.

Requirement 3: Complete The Ultimate Comeback Challenge

This challenge is in the Ace Challenge Pack. You will have to unlock this Challenge Pack before you can attempt to unlock it. Details are explained further down the solution.

Requirement 4: Complete The Retribution Challenge

This challenge is in the Demolition Challenge Pack. You will have to unlock this Challenge Pack before you can attempt to unlock it. Details are explained further down the solution.

Overview

There are 6 Challenge Packs which you can access in the game, but none of them will be available if you have only just started the game. In order to access the Challenges, you will need to reach Level 5.

Once you have reached Level 5 the Challenges selection in the menu will open, but not all of them will unlock. The reason is because you will need to reach different ranks before you can access all of them.

Challenges in this game are specific missions that are placed within the Challenge Packs and your objective is to complete them whilst you race or battle with or against opponents. You will get a message on the bottom left side of the screen mentioning about the progress towards a challenge should you have started it or close to completing it. If you successfully complete a challenge you will be awarded extra Fans (XP) which will go towards your Level Rankings. Going for Challenges in this game is a perfect opportunity to progress towards Level 50 faster.

Most of the Challenges in this game have 3 Stages which you need to complete in order to fully fill up the bars with 100% completion of the Challenge. The 3 Stages usually give you a higher amount of Fans depending upon how much you have to worked on the challenge.

There are some Challenges though in this game that only have 1 Stage and if you successfully complete it, it will automatically fill to 100%. This is usually noticeable in the Daily, Specialist and the Ace Challenges.

There are also some Challenges that require you to use a Mod to help you complete them. Mods are available when you reach a certain rank when playing multiplayer.

List

Here is a list of all of the Challenges in the game. I will provide you information as to when you will unlock the Pack and what tips I can give you should you decide to go forth and complete the challenge.

Car Challenges --- Unlocked At Level 5

There are 4 Classes of Cars (A, B, C & D) and there are 15 Cars in each Class Pack. The Challenges for each vehicles are exactly the same, but some of them will not be accessible until you reach certain ranks in the game. Some vehicles even require you to get to Level 50.

The Challenges for the vehicles are...

Completed Races I - Finish 10 races with this car
Completed Races II - Finish 25 races with this car
Completed Races III - Finish 50 races with this car

Winner I - Finish 1st in 1 race with this car
Winner II - Finish 1st in 10 races with this car
Winner III - Finish 1st in 25 races with this car

If you manage to complete either the Completed Races or the Winner for the chosen car then all 3 bars will be highlighted in Green instead of Orange.

I recommend whilst playing the game to assign 4 Cars of your choice, having 1 for each Class and continue to play and attempt to win races. Once you have raced 50 times with the chosen car then switch to another vehicle. That way you prevent yourself from repeating to play with the same vehicle and lose out on XP for not racing in different vehicles.

Note: Even though there are 15 vehicles in each class and the game lists 30 in the Car Challenge, the reason is because the game has 6 Bars on either side of each vehicle. When either the left or the right side of the bars are all Green, the game will count this as 1.

Drivers Ed Challenges - Unlocked At Level 5

Airbrake - Airbrake with Nitro - The Nitro is the Green Power-Up. As soon as you grab it simply press and hold and then press to use. Can also be done in Motor Mash King Events.

Barge - Barge Cars - The Barge is the Purple Power-Up. Simply grab it and head up to your opponents and then press to shove them aside. Can also be done in Motor Mash King Events.

Bolt - Bolt Cars - Bolts are the Light Pink Power-Up. You get 3 per Power-Up. You just simply fire them with and they will make an opponent lose it's control. Can also be done in Motor Mash King Events.

Mine - Mine Cars - Mines are the Orange Power-Ups. You can either place a Mine behind you with the or if you hold and press you will force it in front of you. Can also be done in Motor Mash King Events.

Minesweeper - Destroy Mines without taking damage - This can be done by grabbing an item such as a Shield and going through the item to prevent yourself from being damaged. Be-aware that you can hurt yourself if you plant your own mine. Can also be done in Motor Mash King Events.

Nitro - Overtake cars using Nitro - Pretty self explanatory. You will need to grab a Nitro and find an opponent, then simply press to use the Nitro to overtake the opponent.

Note: Cannot be done in Motor Mash King Events.

Rear Guard - Block 20 attacks using another Power-Up - If an opponent is trying to attack you with a power-up, you can attempt to avoid the attack by using another Power-Up. When the time is right either press or then if need be to place the power-up behind you to avoid the attack. You can also use shields as well. Can also be done in Motor Mash King Events.

Reverse Bolt - Hit cars using Reverse Bolt - When you have the Bolt power-up simply press then to fire the Bolt backwards. If you hit someone behind you, it will count towards this challenge. Can also be done in Motor Mash King Events.

Reverse Shunt - Hit cars using Reverse Shunts - When you have the Shunt power-up simply press then to fire the Shunt backwards. If you hit someone behind you, it will count towards this challenge. The Shunt can only go straight if it's shot from behind. Can also be done in Motor Mash King Events.

Shield - Block attacks using Shield - The Shield is the Grey Power-Up and if you press to use it, it will protect you for a short period of time. If an opponent tries to attack you whilst you use the Shield, you will not take damage. Time this power-up right and use it wisely. Can also be done in Motor Mash King Events.

Shock - Shock cars - The Shock is a Blue Power-Up. When you grab it you will launch a lightening strike. Anyone who is in front of you will have 3 beams of lightening to avoid. If they hit a beam then you will get credit towards this Challenge. You cannot do this challenge if you are in 1st place.

Note: Cannot be done in Motor Mash King Events.

Shock Evader - Be targeted by Shock and avoid being hit X times - The hardest Challenge in the Drivers Ed. You need to be in 1st place and if an opponent uses a Shock then you will have to avoid 3 Lightening Beams. You will need to slow down using or . You will then need to carefully pass the beams before they disappear. You can use a Shield to pass through them if need be. If you get hit once it will void the challenge.

Note: Cannot be done in Motor Mash King Events.

Shunt - Shunt cars - The Shunt is the Red Power-Up. When fired it acts like a missile and goes for the nearest target in front of you. If the target gets hit, they will go flying. Can also be done in Motor Mash King Events.

Shunt Evader - Evade Shunts - If a shunt is on it's way to hit you, you can use a power-up to prevent yourself from going flying. When the time is right either press or then if need be to place the power-up behind you to avoid the attack. You can also use Shields as well. Can also be done in Motor Mash King Events.

Top Three - Finish 3rd or better in a race - This is pretty self explanatory. You need to finish 3rd or higher in a certain amount of races.

Note: Cannot be done in Motor Mash King Events.

Mine Lobber - Hit 20 cars using forward-fired mines - If you have a mine equipped and an opponent in front of you, you can hold and then press to shoot the mine in front of you. If it hits the opponent, they will spin out severely. Be careful not to hit your own mine should you fail to hit your target. If you don't hit your target it will count as a normal Mine hit. Can also be done in Motor Mash King Events.

Demolition Challenges - Unlocked at Level 11

Brutal Deluxe - Push a car into deep water or off a cliff - There are some maps that contain water and cliffs. Simply find and use a power-up against an opponent and when they spin out or go flying, hope that they do one of the above.

Note: Cannot be done in Motor Mash King Events.

Carnage - Cause the most damage during a Ranked Event - You need to be the player that grabs a lot of power-ups and successfully hits the most opponents during the race. A recommendation is to stay around 2nd, 3rd etc and grab whatever you can find. Then use the items and beat up whatever drives around you. Can also be done in Motor Mash King Events.

Vendetta - Wreck an opponent twice during a Ranked Event - You need to take down someones health twice and wreck them during one race. The easiest way to get this is to play Motor Mash King Events as that event will require you to duel against multiple opponents.

Bruiser - Deal out heavy hits - You need to have the Battering Ram Mod equipped and a big vehicle. As you are driving around simply find an opponent you can bash into which causes them excess damage. You may need some Nitro. Can also be done in Motor Mash King Events.

Brute Force - Wreck cars by ramming into them - If you boost on Motor Mash King event you may get this without notice as if you drive around at top speed and bash into someone who has low health, you will wreck them.

Fully Bolt - Fully Bolt cars - You can use Laser Sight to help you if need be. You need to successfully shoot all 3 Bolts from the power-up and hope that all 3 land on an opponent. Can also be done in Motor Mash King Events.

Light Weight - Deal out light hits - A light hit is when you nudge against your opponent causing them to be pushed aside. You will likely get this one without notice if you boost in the Motor Mash King Event.

Master Exploder - Explode a Mine with another Mine - You need to find a Mine that's placed around where you are and then hold and then press to shoot the mine in front of you. If you cause a mass explosion, you get credit for this challenge. Can also be done in Motor Mash King Events.

Nitro Ram - Nitro ram cars - You may want to consider adding the Battering Ram to help you. This is simply done by bashing into an opponent which is in front of you using the Nitro. You will likely work on this without much suspicion in the Motor Mash King Event.

Nitro Rift - Hit opponents with a Reverse Nitro Rift - This is easily done in Motor Mash King Event when boosting. Park up near an opponent and then hold and press to spark a Nitro attack that will shove an opponent aside.

Bully - Bully cars - This is awarded if you use multiple power-ups on the same opponent without damaging anyone else for a short while. Can also be done in Motor Mash King Events.

Cause & Effect - Hit cars with one Barge - Easily done whilst boosting in the Motor Mash King Event. Get everyone to group up and when it's your turn to attack, squeeze in with a Barge and unleash!

Punisher - Wreck cars during a Ranked Event - You need to wreck a large amount of vehicles in one race and this isn't easy because if someone gets wrecked, their health returns to normal. You will have to do this in Motor Mash King Event as there is no chance in getting this in a race.

Retribution - Perform 5 Revenge Attacks during a Ranked Event - REQUIRED FOR ACHIEVEMENT - You need to get an opponent to attack you and then you need to attack them back to earn an Revenge. It can be the same opponent who attacks you as long as you successfully let them get you first, then you get them back. You can do this in a race but it may be easier in Motor Mash King if you co-ordinate with your boosters.

Rivalry - Wreck your Rival X times - Easily done in Motor Mash King Events. A rival is an opponent you are assigned with at the start of the event. But if you get wrecked by someone else, they will become your rival instead. When it's your turn to play simply attack normally and if your rival gets wrecked, it will count towards this challenge. Eventually you may get more rivals after you wreck multiple people.

Wrecking Ball - Wreck X cars - Pretty self explanatory. You need to wreck a large amount of vehicles. Motor Mash King is probably the best game mode to get this done.

Daily Challenges - Unlocked At Level 13 - These Challenges get reset on a daily basis and you can re-use the same challenges to build up more XP.

Face Plant - Crash into 100 cars - This is easily done by crashing into another opponent during a race. It can be the same opponent as well. It may not count though if you get hit on the side or behind. Can also be done in Motor Mash King Events.

Hard Day's Work - Win 5 races in a day - Not easy as the people who play this game now are dedicated or pro players. I recommend you attempt to place yourself in a group of friends and trade wins if you want to try and go for this challenge.

Note: Cannot be done in Motor Mash King Events.

Overtake - Overtake 100 cars in a day - If you remain around 3rd or lower in a race and use power-ups, there is a chance that you will overtake opponents easily. You will likely get this without too much notice.

Note: Cannot be done in Motor Mash King Events.

Participant - Finish 20 races in a day - Easily done if you just take part and complete 20 races from beginning to the end.

Note: Cannot be done in Motor Mash King Events.

Pied Piper - Earn the most Fans in a 20 Player Race - It will be extremely rare to have 20 people in a lobby at the same time. But if you do have this option make sure you have the Fan Favorite and Showy Flourish Mods placed in as they will give you extra Fan (XP) towards this challenge.

Note: Cannot be done in Motor Mash King Events.

Demolitions Expert - Wreck 50 cars in a day - Better to be done in Motor Mash King Event. You will wreck cars whilst you are boosting with your group so if you commit to the boosting for a short while, then you will get progress done towards this.

Distance - Drive a total of 150 miles in a day - This depends upon how much commitment you play multiplayer in the game. If you can sit and race for an extensive period of time in the day, then you will easily get this challenge without problems.

Note: Cannot be done in Motor Mash King Events.

Hoarder - Pick up 500 Power-Ups in a single day - Find a power-up and grab it... In fact grab as many as you can. Like Distance you will need to commit yourself to the game for the day if you want a chance to get this challenge. Can also be done in Motor Mash King Events.

Aggressive Personality - Hit 250 cars with power-ups - You will easily get this if you stay around 2nd or lower and use any power-up you grab that can damage opponents. Like Distance & Hoarder you will need to commit yourself to the game for the day if you want to easily get this done. Can also be done in Motor Mash King Events.

Car Crazy - Use 30 different cars in a singe day - As soon as a race is completed, switch to a different vehicle each time before a new race begins. Can also be done in Motor Mash King Events.

Chain Reaction - Achieve a 10x combo - A combo is when you manage to damage multiple opponents in succession. It can only really be done in Motor Mash King Events because you will need to find a way to damage 10 opponents without losing your streak. It's possible to damage the same opponent for the streak to continue, but remember that if you've just damage someone and they disappear, they will respawn and have temporary spawn protection. This is a hard challenge and not recommended for racing.

Hat Trick - Win 3 races in a row - The people who play this game will not give you a chance in winning as that's what they always want, so if you want to get this your best bet is to boost in Motor Mash King.

Head In The Clouds - Spend 10 seconds in the air - This is across all of your races played in the day. As you race simply find an area that requires you to fly up and be in the air for a few moments. Commit yourself to playing the game for the day and you will easily get this without any problems. Can also be done in Motor Mash King Events.

Well Traveled - Visit each country in the game - There are 4 countries you can visit in the game. They are Japan, Spain, the United States & the United Kingdom. You are automatically awarded this as soon as you start a race but the game will randomly choose 2 tracks for you and everyone to pick. You need to pick the area which you haven't raced yet in the day and if your successful to get the track you wanted, you will get progress towards this.

Dominator - Stay in 1st Position for a total of 15 minutes - This can only really be done if you are racing with a group of friends and taking turns for winning or if you are winning in Motor Mash King Events. However this will come naturally if you remain at the top for the extensive period of time.

Style - Pull off 500 Scoring Moves - This is done by successfully performing any attack or move that gives you points. If you commit yourself to playing the game for the day, you will get this without much notice at all. Can also be done in Motor Mash King Events.

Specialist Challenges - Unlocked at Level 19

Afterburner - Win a race using only Nitro - I would only recommend you do this challenge if you are boosting races with a group of friends and no randoms are in your way.

Note: Cannot be done in Motor Mash King Events.

Backwards Thinking - Win a race using only backwards attacks - I would only recommend you do this challenge if you are boosting races with a group of friends and no randoms are in your way.

Note: Cannot be done in Motor Mash King Events.

Barge Specialist - Win using only Barge for 1 race - I would only recommend you do this challenge if you are boosting races with a group of friends and no randoms are in your way.

Note: Cannot be done in Motor Mash King Events.

Bolt Specialist - Win using only Bolt for 1 race - I would only recommend you do this challenge if you are boosting races with a group of friends and no randoms are in your way.

Note: Cannot be done in Motor Mash King Events.

Jumper - Perform 3 Nitro jumps in a single race - This can easily be done if you can find ramps on the track you are racing on. I would suggest you aim for this challenge only if you want to lose the race and grab as many Nitro's as you can find on the track. As soon as you see a ramp hit the button to boost over it.

Note: Cannot be done in Motor Mash King Events.

Mine Specialist - Win using only Mines for 1 race - I would only recommend you do this challenge if you are boosting races with a group of friends and no randoms are in your way.

Note: Cannot be done in Motor Mash King Events.

Pacifist - Win a race without using any power-ups - I would only recommend you do this challenge if you are boosting races with a group of friends and no randoms are in your way.

Note: Cannot be done in Motor Mash King Events.

Adaptive Shielding - Absorb Power-ups with the Adaptive Shielding Mod - You will need the Adaptive Shield Mode in order to do this challenge. As you race you will need to grab obstacles using the Shield Power-Up for this to count. An easy way to do this is to grab a Mine and shoot it in front of you, then use the Shield to grab it. Can also be done in Motor Mash King Events.

Battering Ram Mod - Hit cars with the Battering Ram Mod - You will need the Battering Ram Mod in order to do this Challenge. It is easily done by hitting opponents with your vehicle and making them take damage. You will likely get this without much notice. Can also be done in Motor Mash King Events.

Deceiver - Hit drivers with Decoy Drops - With the Decoy Drops, press the to drop an item that looks as though it's something someone else can grab. When they grab it though it will blow and cause them excess damage. Think of it as a Fake Box from the Mario Kart games. Can also be done in Motor Mash King Events.

Drifter - Earn Nitros using the Drifter Mod - You will need the Drifter Mod. Whilst this is equipped you will need to perform a Super Drift. Doing so will give you a Nitro. This isn't easy to do as you will need a car that can drift and go out of control easily. If you are planning on winning the race, I wouldn't recommend this challenge at all. Can also be done in Motor Mash King Events.

Master-Mine - Trigger Mines using the Master-Mine - You will need the Master-Mine Mod. This is easily done in the Motor Mash Event. Whenever you see a planted Mine (yours or an opponents) simply drive into the outer shell of it (do not hit the black part). You will explode the mine and scatter pieces around it. The pieces will act the same as a normal mine if someone hits them.

Road Sweeper - Collect Power-Ups with the Magnetic Field Mod - This is easily done in Motor Mash King Events. This enabled mod will grab any power-ups that are nearby you but you missed them as you drive.

Scrambler - Scramble cars with the Scrambler Mod - You need the Scrambler Mod to do this challenge. Whenever you shoot a power-up from behind with , any opponent that gets hit will have their power-ups disabled for a short moment because of the Scrambler being activated. Can also be done in Motor Mash King Events.

Stealth - Overtake cars while invisible using the Silent Running Mod - You will need the Silent Running Mod to pass this challenge. After driving for a short while your car will go invisible. You cannot use any power-ups and you will not hit anything. You must keep at a high speed or you will be visible if you slow down. You need to hope that you are still invisible when you overtake an opponent during a race. You cannot bash into opponents whilst you are invisible neither.

Note: Cannot be done in Motor Mash King Events.

Last Gasp - Hit cars using the Last Gasp Mod - This is easily done in Motor Mash King Event. When you get Wrecked you have 10 seconds to press to activate the Last Gasp. This will explode your car before you respawn again in battle.

Ace Challenges - Unlocked At Level 30

Chosen One - Fire 6 Reverse Bolts, landing with each shot while driving fast - As you are racing you need to grab at least 2 Bolt power-ups and have an opponent behind you. If they stay straight simply fire away by holding and pressing . Make sure your at a fair speed when doing this. Can also be done in Motor Mash King Events.

Extremely Extreme - Jump 150 meters in a single jump - Your best bet is to keep on racing and find a jump at some point which will make you stay awhile in the air giving you this amount of distance towards the challenge. Could maybe be done in Motor Mash King Events.

FTL - Maintain 225mph for 5 seconds - You need 3 Nitro Power-ups and a straight road with no obstacles that you can use to go at top speed without anyone interfering. You will need A Class car as well, otherwise you will have no chance in accomplishing this goal.

Note: Cannot be done in Motor Mash King Events.

High Slider - Drift 175 meters or more in a single drift - You will need a drifty car and then you will need to play Motor Mash King. Find an area where you can easily spin around and you should be able to get this.

Quick Draw - Wreck 3 cars in 5 seconds - You'll have to boost for this in Motor Mash King. Easiest solution is if your the person doing the wrecking, get 3 opponents down to the weakest point of health, then squeeze them together and use an attack such as Barge to wreck them all at once.

Tearaway - Finish at least 30 seconds ahead of 2nd place - You will need to be very good at the game and that's not easy because of pro players. You need to win the race in first and then make sure no one crosses the finish line in 2nd place for at least 30+ seconds. The timer is in actual fact around 30 seconds so in reality, you have to hope that everyone gets DNF apart from yourself.

Note: Cannot be done in Motor Mash King Events.

Ultimate Comeback - Get into 1st place, then last, then win the race - REQUIRED FOR ACHIEVEMENT - You can do this with a group of friends or if your lucky enough in a 1-v-1 with your boosting buddy. It can be a bit tricky to register this challenge though.
Get everyone to cross over the start line when the race begins and then have the person going for the award to start in 1st place. As they race for a bit, get everyone then to take over the winning person and put them in last place for a period of time. Then slow down and let the winning person take the lead and complete the lap.
It's recommended that you perform this challenges requirements on each lap for it to fully register.

Note: Cannot be done in Motor Mash King Events.

Skeet Shooter - Wreck an airborne player - You'll have more of a chance in getting this in Motor Mash King. If it's your turn for wrecking, get someone down to low health and then launch an attack whilst their mid-air and hope that they get wrecked whilst they are up in the sky.

Aim To Please - Earn 1000 Fans in 30 Seconds - This is a very hard challenge and your only chance of getting it is via Motor Mash King. You will need to keep on attacking every opponent around you and build up a very big combo for a chance to succeed.

Unguarded - Complete races without using a Shield - This one will come naturally. Simply do not use a Shield whilst you are racing on the track. If you grab it, press the button to drop it. You do not have to win the race for this challenge.

Note: Cannot be done in Motor Mash King Events.

Thick Skin - Complete races without using a Repair - This one will come naturally. Simply do not use a Repair whilst you are racing on the track. If you grab it, press the button to drop it. You do not have to win the race for this challenge.

Note: Cannot be done in Motor Mash King Events.

Untouchable - Take no damage for 5 races - This can be done easily with a group of friends willing to boost with you in races. Let your friends go ahead and win the race and stay behind without getting damaged by them or the obstacles on the track. You do not have to win the race for this challenge.

Note: Cannot be done in Motor Mash King Events.

Rampage - Wreck 10 opponents in a race without being Wrecked yourself - Very hard to get. You will only have a chance in doing this in Motor Mash King Events. Have everyone grouped together and hope on multiple occasions that their health will get very weak. Then simply finish them off with a final blow to wreck them.

Sidewinder - Drift into power-ups - This isn't easy. You need to perform a drift-like move and grab a power-up at the same time. You may get some of these done without notice, but you may not expect it unless you commit yourself to the challenge. Can also be done in Motor Mash King Events.

Elf Eyes - Score Long Shot Bolt Hits - You need to equip the Bolt Power-Up and have an opponent a fair distance ahead or behind you. If you successfully shoot the bolt in either direction and it's a hit, you will gain credit for this challenge. It may be possible to do this in Motor Mash King but you will need some distance away from your opponent which may be difficult on some maps.

Outcome

You do not need to complete every single challenge in this game in order to get the achievement. However if you focus on the easier ones then you may get the achievement earlier than you anticipated. In addition the XP given will allow you to progress towards Level 50 faster.

If you need information on how to organize methods for reaching Level 50 or for a guide into boosting in the Motor Mash King Event, here is my solution...

Solution for Living legend? In Blur

I hope all my information for this solution is useful.

Good Luck!