Is it too late to get this lemon fixed?

I bought a used car from a little redneck dealership. By the time I noticed something was wrong with the car and took it to the shop it had been past the 30 day warranty by about two weeks. But it is obvious the car was sold to me with the problem. the mechanic says it might be missing a support brace that holds in the transmission in the driver's side, that and a few other minor repairs. He told me to call the place I got it from and see if they would help me, But it's past the warranty so I don't know if they would do anything. The dealership "took the car to get it inspected" before I drove off with it, but I feel like they would have noticed such an important part of the car missing. Can I argue this with them and get an extension or should I bother calling those crooks?