I am literally blown away at the number of people who think that there is even a remote possibility that the dealer would be liable for providing a new car replacement! If that were ever to happen (and it's about as likely as winning the lottery), it would only be the dealer making some sort of good will gesture - or as a normal trade in. There is no way you would ever show they are legally liable to replace the car. Their legal responsibility is to put the car back to the same condition OR to make a monetary settlement equal to the loss of value. That's it. They could offer you something like $1000 (or whatever loss of value is determined) and tell you to go away. If they can do the body work in such a way as to be unnoticeable (something a good body shop can do well) then that's all they are responsible for.
Your feeling that the car is not the same because it's been repaired has absolutely nothing to do with it.
2011 Pony Pkg. convertible M6
Am WS7 (sold)