I agree that the dealership should sell you the car at the specified price, but this is a no win situation. You are going to spend a lot of money chasing this down and negate any savings. Being a large dealership they probably have attorneys on staff so it does not cost them much to fight this.
The path that I would pursue is just have them sell you the car at invoice. You will have the best price in the country at that point and you are not asking them to take money out of their pockets. The dealership will probably be more amenable to this than selling the car for $60K