Forza Horizon 2

The easiest way that I found to do this was to join one of the popular public clubs (for example, Major Nelson's) with hundreds of people. Then find the two speed cameras right outside of the horizon festival and just drive back and forth across them with your fastest car. You may want to start a bit slower and gradually increase your speed with each pass.

Since so many people are in the club, you're bound to beat someone every time. It took me less than 10 minutes this way.

This solution may have diminishing returns as more and more people play the game and get higher speeds. Find some of the more out of the way speed traps if that happens or find smaller clubs, best their times, and move to a different club.

For some reason Majorpoopy's solution didn't work for me, seems like other had the same problem as well. When I pass through a speed camera the only way I could get it to count was from beating the person it paired me up with. It also didn't help that my personal best was 145 but the next one was at 206. A lot of the cameras had ridiculous gaps and I think it was because I was in a fast car. So here's what I did:

I grabbed a A class car, 1970 Corvette ZR-1 in my case(A800)
Then I looked for the lowest record I had, southwest of the Horizon Festival not far from the LaFerrari bucket list, West Cliff speed trap. It's on a turn so I only had 75.
I barley beat that score with like a 76 and got some progress for the achievement.
Now when I beat that score, nothing happened, there was no one else to beat. So I loaded up the leader board to make sure there were club members to beat and sure enough there was. Beat my score again and this time I beat a club member. So now after every time I beat someone I made sure to load up the leader board so it can load up the next person for me.
I did this 9 times barley beating my score, got it all the way up to 104mph.

TLDR: Actually solution without all that reasoning.
1.Grab an A class car
2.Find lowest speed trap
3.Slowly beat score by as little speed as possible and make sure to load up leader board once you do beat someone. Just enough for it to load, then you can close it.

Personally I struggled with the other two solutions. This is what Worked for me.

Firstly make sure you are in a club so you have more people to go up against. You need to complete the Train In Vain event before you can join a club. The more people the better.

Go through a speed camera at a reasonably low speed. Your speed will be shown at the bottom of the screen and a few seconds later you should see your speed and a rival’s speed with the option to see the scoreboard (you do not need to view it). If your name moves above theirs, congratulations, you just got your first one.

If your name stays below theirs, make a note of their speed, then go back past the camera making sure that you are just above it. When you and the rival are displayed, you should then move above theirs.
Now go through again a fraction faster. You should get a new rival and you can repeat the process until you get 20.

If for some reason it stops displaying your name and a rival, move to a new camera and start low again.

If you make a mistake on approach to the camera and get slowed down, use the rewind a couple of times and try again. I found that 2 rewinds were better as sometimes using just the one meant the camera didn’t flash at all and was out of action for a while.

If the camera do ant flash when you go through, you will need to move to a new camera.

I hope this helps someone as I found this very frustrating and took ages for anything to register. I checked the achievement tracker each time to check it had registered.

Good luck.

If u have a glitch and stuck as me see this. Helped me 100%.
I unlocked now. How i do it. Easy.
I Join in new Club (don`t exit before from Current club). After joinning i go to speed cameras and my progress go up. Its worked, guys!
Its glitch of Club - if i after Join again to my Old Club - again error - i see only my previous best time PB! And i cant see popping message with speed of club members.
Glitch Club - RUS The Saints (999 members)
Worked ANME Anime
FRWL From Russia With Love
Maybe glitch in clubs with 999+ members only.
Sorry 4 my bad English)

Just a small additional tip:

From my (limited) experience, it would seem that beating someone will only count toward the achievement if you beat them with an equal or lower class car than they used. Worth a try if you're struggling like I was.

This solution is meant for those trying to pop "online" achievements like this one in 2022 and beyond. The servers are extremely temperamental nowadays which affect the progression of the following achievements:





First, make sure you're in a Car Club with a large amount of members. Pick any club from "Recommended Clubs". This makes it so you will have more people to beat on the leaderboards instead of just people on your friends list.

(Press , go to the "Club" tab, select "Join New Club", then "Recommended Clubs".)

Before you attempt to post any speed camera times, make sure you're connected to the Forza Servers. A connection is needed in order for the achievement progress to count!

You can do this by going to Solo Free-roam, pressing then trying to load "Vinyl Groups" in the Community tab. As soon as you see some designs load, go straight to any speed zones/traps you plan to post a time on. Alternatively, you can press then go to your World Map, go to any desired speed zone/trap icon & press to view the leaderboard.

You might need to keep checking if you're connected to the FH2 server after you post up a time. In my experience with attempting to pop this achievement, I'd lose connection unknowingly after going to my 3rd speed trap/zone.