Here's a picture of my control settings

What you have to do is go to any of the challenges and start on 2nd gear shifting up to 4th gear

(NOTE: I personally prefer manual shifting because it's easier to control your car; Gear up = A | Gear down = Z)

Once you got up to 4th gear make sure you keep your car going with about 4000rpm and 50-60km/h and then try to make a big circle steering left or right (whatever you prefer)

(NOTE 2: You don't have to pass the checkpoints to finish the challenge! Score multiplier will raise itself)

This is how your car should move:



Depends of the time, you can reach over 30 000 points once you learn how to keep your car in moving around

Final result:



Enjoy the gold medals :)
Hope you like it