Forza Horizon 3

Take a fast C-class car and drive to Rainforest Reveal Danger Sign and jump atleast 91 Meters.
If you need a little extra speed, you can allways drive upp the hill and gain a little more speed right before the jump.
If you fail or hit a tree, you can allways rewind with

I Jumped around 93 Meters with a Buggy C class 520 points.
Speed is 3,5.

Edit: The Ferrari Dino you get from a Barn Find can do this easily
Thnx WinMo Kirby for the tip

Car: 1974 Toyota Celica GT (D176)
Tune Creator: "Don Joewon Song"
Tune Name: "230+MPH C-Class" [C600]

The above car and build is an absolutely BEAST for a C class car. It can outdrift and outrun most B class cars. It was an incredible high speed, and just enough power to solidly drift through any turn.

With this build, go to the "Outback Trail Drift Zone", close to The Outback festival hub and with just a little bit of practice, you should be able to easily get the 45,000 point requirement done. I would suggest using this car for ALL of the drift zones in the game in order to easily get 3 stars.

If you prefer driving in a straight line instead, go to Surfer's Paradise Festival Hub and go for the nearby Speed Trap approaching from the bottom. I was easily able to get 20+ mph over the requirement for 3 stars. Use rewind if you need it.

Barn Find Car: Holden HQ Monaro GTS 350
PR Stunt: Rainforest Reveal Danger Sign
91M = 3 Stars

I just took the fastest sub-B base car I had in my garage and upgraded as much as I could with speed and acceleration while keeping it under C class. Then I took it to the danger sign at the plant with all the pipes west of the outback festival. That jump has a nice easy run-up and doesn't require a huge jump. If you get a good run-up, just keep rewinding until you get the perfect launch and you should go far enough in just a few jumps.

This is useful for all Drift Zones if you are having trouble getting 3 stars on all of them. By far the best car I have used for Drifting is the Ferrari 166MM Barchetta 1948

It is expensive so get it from Auction, during a sale or use your boss perk from the skills screen to get it.

I've made a tune for it, it should be the first one you see if you search by Drift. You only need it tuned to max C class so this will also help you get the PR Underdog achievement. To get 3 stars in a C Class Car. I did this by hitting the Drift zone right in front of the Outback Festival, Outback Trail. I got 50,000+ on my 2nd attempt!

I'm not great at Drifting but I got 3 stars on all Drift Zones usually in 1-3 attempts. So check it out!