The race track is where most good things in a car begin their journey towards becoming an everyday consumer item. You can think of just about any feature on a car and find a way to tie it back to the track.
Donut Media created a short video to outline some of the most important inventions to have begun life on the circuit. Seriously though, you'd need Ken Burns to direct a video including all of the developments. It'd be a long movie.
Most of these changes are obvious, even before you spend that much time on them: aerodynamics, making cars faster and more efficient; disc brakes replacing the less reliable and harder to maintain drum brakes; and turbo chargers. All of these inventions found their beginnings on a race car.