Grease Dance

Here’s a guide and it’s only a guide which references how I did it. You may find an easier route.
Before trying to set the 250,000 high scores in your 3 games, be aware and attempt these achievements to the point where you are at least sure you could get it with some practice. More than likely, you’ll unlock most of these when you go for your high score.
Let's Get Nuts (tighten 8 nuts)
All the way home (hit 5 home runs in a row)
Basket Case (hit 5 baskets in a row)
Hit it (flatten 3 bumps)
Road Hodge (hit no obstacles in the race)
Here’s the mini games you’ll need to do.
Greaser’s Garage (250,000) I scored 310,000.
This is made up of 3 games within the game.
Flattening bumps. (60-90,000)
The key here is panels, you should clear 3 panels often enough, there’s only 5 bumps per panel. The key for me was aiming by leaning and keeping my arm cranked for the hammer swing at all times, and only moving my arm to swing. You must strike while the indicator is in the white zone. The white zone will either be in the middle of the gauge, or at an end. If it’s on the end, it’s easy, but if it’s in the middle, you’ll need to start your swing while in the yellow. You get 30,000 per panel and should make 60-90,000 for this game. 1000 per bump, and 25,000 for clearing the panel.
Tightening the nuts. (50-70,000)
This game takes some practice, but is very consistent once you get it. You have 4 basic actions, Search, Hold, Crank, Drop. Search with your right, when the wrench locks on, bring up your left told hold, and start cranking. When you hear the “ding” or notice the wrench start to struggle, drop both hands. If you drop hands correctly, you score 10,000 points. If you don’t see the 10,000 points per nut, which is possible, pay more attention to what you are doing. It’s possible to clear all 4 nuts and not get your 10,000 points, so drop your hands correctly seems to be key. You score tons of points on this game, but you absolutely must get that 10,000 point to flash each time you finish a nut. It’s really not that hard.
Painting (75-100,000?)
Clearing 3 panels of paint seems to be a good idea. Never stop painting even if you don’t think you’ll complete a panel, because each drop is worth 100 points. The white paint, I rarely if ever can get done with one can, it usually takes 1 and a half. Shake between panels. Shake with two hands. You don’t have to be incredibly accurate on the lightning bolts, just get paint into each bolt. If you are shaking, always shake till it is full. Do not try to fill a can up half way, it will only cost you time.
Greaser’s Vs Jocks
Wrestling (90-120,000)
Move in tight circles until you are clinched, then circle your hands forward to imitate a lunge. You should get the pin in a matter of seconds, the hardest part is getting him to clinch if he moves away. That’s why you should get used to walking in tight circles. I always stay hunched over for the whole match. 15,000 per pin. If you don’t score at least 90,000 per match, you’re doing it wrong.
Baskets (60,000 +)
Simply hit as many baskets as you can. Hold arms up, jump, and release just before you hit the ground. Having palm over palm helps. Go see the “Basket Case” guide as you’ll likely get that achievement at the same time as this.
Home Runs (60,000 +)
Simple hit a lot of home runs, 10,000 per. You really must be locked in and swing early so the ball is right at a certain point in the middle of your swing. Swing from your hip across your chest to the top of your ear as has been said in the other guide about how to hit home runs. If you get 5 in row, the other achievement will also unlock.
Thunder Road Race
The Road Hodge achievement is closely linked to this, but I don’t think it’s possible with one player. You can still get 250,000 with one player on this, as that’s what I did with enough tries. The key is to get up into 3rd gear and stay there. Gear up whenever you hit an obstacle, at the beginning of the race, and in the middle when you turn around. If you are hit by the opponent, which will randomly be aggressive at times, you’ll gear down. Just gear back up into 3rd often, and avoid obstacles. The other really big key here is to avoid obstacles. Each obstacle you avoid nets you 500-1000 points. Staying on the side is the important part, because puddles count and they are hard to see. Don’t be afraid to drop down to the road if there are too many obstacles on the side, just jump back up to the side quickly. You should score 50,000 points by the half way mark and 100,000 points by the end of the race, plus 150,000 for winning the race. You won’t win the race if you aren’t in 3rd gear, so get up to gear by the end of the race for sure. Being in gear is also the best way to avoid the other driver. That should get you exactly 250,000 or a little over that. You’ll need to hit probably less than 10 obstacles for the entire race to get the score. The race track is not random! That means you can memorize the track. For instance, getting into 3rd gear, and moving up on the left at the beginning of the race, then quickly crossing all the way to the right before the bridge, you can be at zero hit obstacles for a while. Memorize a few tricks and patterns like that and you’ll do fine.

I recommend doing this achievement in competitive mode against a dummy or live player to make it easier to score on some sections. It's worth noting, you can also earn this achievement while working on Buddy Lovin' in 2 vs 2 competitive mode, as the main player will want to go for at least 250,000 points on each Kinect section.

The modes I played are Greaser Garage, Greaser vs Jocks, and Thunder Road Race.

Greaser Garage:
This game type is broken down in to three games; hammering dents, tightening wheel nuts, and spray painting the body of the car. I did this mode with a dummy and managed a score on Kinect of 298,000.

Tips:
Hammering dents: You will want to aim for clearing a minimum of two full car parts of dents for the bonuses, but the goal is three. You will not need a live player to help, but if you do, you can have them hammer dents out to speed up the process, as you will score more points clearing all dents than you would doing individually doing them all yourself. Although this can help clear an extra car part of dents for the bonus, the opposing player's meter is faster, which could make this harder to accomplish. Recommend you do this part solo.

Tightening wheel nuts: This requires the player to quickly lock on and tighten the wheel nuts as they rotate around in a circle. This isn't too difficult, and the player should aim for at least 6 nuts in a run. Note, as you crank the last crank of the nut, you'll notice the crank slows. As the crank nears the end, drop your arm and wait for the wrench to disappear. This nets 10,000 points for each nut. Clearing all four nuts will net a bonus. In competitive mode, the opposing player can hold your wheel by hovering over a nut on your wheel and maintaining it. Once the player is down to the last nut, quickly shift the opposing player off so you can quickly crank it. The opposing player can then hover over a completed nut on your wheel, which will automatically lock on once the wheel refreshes. This keeps the wheel from spinning, making it easier for the main player to hover over the next nut.

Spray painting: This needs to be done solo. Quickly paint back and forth, starting from the top and making your way down left to right. Quickly shake the can to recharge the paint. Once the car is painted white, you'll want to quickly paint the red stripes. Clear at least three fully painted parts for the score bonuses, four if you're quick and lucky.

Greaser vs Jocks:
This game type is broken down in to three games; wrestling, basketball shots, and homerun derby. This is the easiest mode in my opinion, but I happened to struggle on the scoring of singing during my run. My Kinect score was 340,000. I personally believe a player can easily hit north of 400,000 points with a really lucky run on Kinect.

Tips:
Wrestling: This game mode would benefit from the opposing player leaning forward, allowing for the main player to quickly lunge forward and complete the tackle during the wrestling. A player can easily score 180,000 points alone in this portion of the game.

Basketball shots: This will be solo, as the opposing player can't assist aside from not sabotaging the main player. You will want to jump high, and then push your arms out just before your feet hit the ground. Getting in a rhythm on this portion can be frustrating.

Homerun derby: This will be solo, as the opposing player can't assist aside from not sabotaging the main player. Similar to the basketball shots, you will want to try to time each swing. Finding the timing can be difficult, and I found the game to register hits totally randomly. One time I hit homeruns 10 times in a row for 100,000 points, then the next time only hit 2-3 home runs.

Thunder Road Race:
Thunder Road Race can be quite difficult doing against a bot, so it's imperative to do this in competitive. The race is broken down in two sections, with the winner getting a solid 150,000 point bonus. My Kinect score was 259,000.

Tips:
Against a dummy, you can easily knock their car to the right, making it easier to navigate the beginning of the course and then quickly going far left and sticking to the left for the remainder of the race. You will essentially do this at the beginning of each section. Once you get left, shift the car in the next gear to maintain first place for the win bonus. You want to have roughly 58,000-61,000 points on the first stretch and a combined over 100,000 on the second stretch. If you try this against a bot, the bot will ram you and also hit obstacles, effectively eliminating the point threshold needed on Kinect.

My Setup:
This is subjective information, and will not guarantee similar results. My Kinect sat centered in front me, roughly 21 inches from the ground. My Kinect after adjusting itself at the beginning of start up, would be pushed down one notch (it will click), then lifted up as far as it would go without clicking. My lighting was overhead, usually dim, soft white. I would not allow any sunlight through the windows. My space was generally open, leaving around a 10 feet by 10 feet space.
It's worth noting, I was 6'1'', 210 pounds at the time. My size may have played a factor in the tracking of my Kinect at certain intervals.