10 years ago, I was able to see the Xtreme Gravity Racing Series (a charitable event) that had huge corporate support and allowed the use the world's top car designers and automotive engineers (Art Center, Pininfarina, Volvo, Bentley,Audi, VW, Nissan, Chrysler. Mazda,etc). International design studios located in Southern California were well represented, they were allowed to have fun and showoff their creativity, very slick aero concepts and unique suspension technologies. They had a short straightaway in Irvine and longer road course Tuna Canyon hill in Malibu. Check out their advanced ideas and designs (2005-2007).
Xtreme Gravity Racing: Soapbox Derby meets Formula 1
https://vimeo.com/1997214
World-record gravity racer uber design.
Goodwood Festival of Speed; more for fun, shorter wheelbases and handling more important.