You Hit Nothing!
You have completed a Career race without colliding with another car or object.

This is easiet done on a short 25% race distance, it helps to qualify on Pole Position and get a good start, you should not even see another car for the whole race and as long as you do not hit any barriers or signage you will get the achievement at the end of the race.

USA is a good track for this as there are few barriers.