After reading this thread I was dreading the race missions. I put them off until just before the final mission of the game. I have to say, some of you guys need learn to be patient. With the exception of race #7 I did them all within 2 or 3 tries. Some of them on the first attempt. They are incredibly easy!
As for race #7, either use a heavy duty vehicle of use the gyrocopter, its no problem at all.
If its true that what you donít know cant hurt you, then you must be practically invincible!