I have an idea for a class and I'll join any club that has it: Badly battered, ragged out, and rusty mostly Kermit The Frog green 1968 American 4 door sedans. My car would kick butt in that class.
The hotrodders have such a class -- beaters! I've been to a big national that ran one, it was kinda fun. Some of them are junkers you get to laugh at, but there's also the mechanically solid but ug-lee ones that are pretty admirable, cars that have been in use since new, maintained but never restored, crap interiors and paint but nice brakes and solid engines, that sort of thing.