"used to be"? When is that? There are lots of very interesting old stories about rule bending in Nascar. Actually, it apparently started from the very first official Nascar race [1].
If you want racing series about driving civilian cars fast, they do exist. Nascar just isn't one of them. The only one I really heard about is "Stock Miata" racing, but I'm sure there are other series using stock street cars, or at least having the exact same cars for all competitors.
If you want racing series about driving civilian cars fast, they do exist. Nascar just isn't one of them. The only one I really heard about is "Stock Miata" racing, but I'm sure there are other series using stock street cars, or at least having the exact same cars for all competitors.
[1] https://www.theglobeandmail.com/globe-drive/culture/commutin...