Racing has led the development of more economical, lighter weight, and more powerful cars that handle better and stop faster. No other development method has made such rapid progress in automotive technology.
I'd have to agree with that. I'll add that "customized" cars, mostly built in small shops and home garages, have also had a huge influence in the evolution of automobiles.
For example, in the `50s custom car builders were "sectioning" the bodies and "Z-ing" the frames to make cars thinner and lower to the ground. By the `60s all the big manufactures were building cars styled like that.
But racers have had a huge influence on mass production cars and still do. One simple example of that is the coolant overflow tank. As I recall it was small circle track racer that made that mod to his race car and encouraged other car owners at the track to install them because when cars overheated and blew coolant on the track it caused delays in the races. If I recall the story right he had to sue the car companies to enforce his patent and collect a royalty.
