On the map "downhill" you may find youself flipping. Heres hjow to prevent this. At first put the pedal to the metal. Then let go when in mid-air. if you start to flip or even spin do not hold down A or D otherwise you will spin even more. Lightly touch the opposite key to the way you are turning. Touch it how ever many times you need to, to prevent you spinning. I do hope this helps.
Note
This is for any level but on "downhill" it applied more when i was attempting this level !!!
