Drive into a platform you're supposed to jump over, get out, run and jump on the platform, turn around and look at the carthen while in the same view, get in the car then go,you should be able to go over the platform. Make sure you run into the platform hard and straight but don't get out when you bounce off. Be grinding against it.
type in at menu left,right,left,right,select
type in at menu up,down,up,down,select,select