The best way to make a small fortune in the race track business is to start with a large fortune
I'd be afraid of the insurance headaches and cost, and the environmental compiance issues. California is not a good place to build a race track IMO. Heck, it isn't a good place to start any business. The bleeding heart tree huggers have pushed through so many laws that it is almost illegal to have a business here.
Plus we would have to build it out in the middle of the desert, that's about the only land left here that doesn't already have houses on it