The glitch we found.
Buy a car, install nos (just that). Don't fill up the nos tank either. Optimize your engine for best cooling.
Start a race. While the light is counting down, mash the N button. As soon as the light turns green, hold N and you'll take off. Be ready to shift really fast.
I'm pretty sure that's how. EcianIce should be on here eventually and will correct me if that doesn't work. lol, it was about 6 months ago we played that.