The most I have saved would be ~$6000 off my '12 accord coupe. Even "negotiated" the terms of the financing (if you look, they required notice IN WRITING of any mods you do..), got some free coolant, oil, wheel/tire, etc. When I left, I was happy. The salesman was the man. And the manager realized he got bent over for thinking he was going to screw over just "another kid".
<3 my car.