I know how faster get 1mil, you need do everything like in this video, at the start you need to drive to the left bumper, and do nothing, your bus will spin and you dont get point for tricks, and when you land on the ground you will get only 1 tricks, its cost 20-30k, and if you make more "X" multiplier, you will get 100k in 20 seconds.
This method easier, write to me if you need help.