One of the most respected "amateur" racers I know campaigns 3 cars. He has a built/modified 30 yr old honda CRX, a Miata, and a quarter million dollar McLaren. He built his reputation in the CRX and Miata. Check out Andy Hollis. I'm not sure I'd ever challenge one thing he ever had to say about cars.
I very briefly worked for Andy on a project. Nice guy, very focused. He's got what everyone wants and he's actually satisfied with it, which is rare I think.