Purchasing a car from a body/auto repair/tow shop?

I have a mazda6 '09. Excellent condition, but i'm looking to buy a smaller car as a 4 door car is too much space. I've been told to find some auto shops which might have some coupes in hiding (like hidden gems) that can be found in vegas. Does anyone know of such places to check out (that can be trusted)?

I'm not interested in visiting an auction. Been there done that, not the nicest collection :/