You can take a car back up to 72 hrs after the paper work is signed here. Dealers don't like it and its not publicized. It is done.

I took a Subaru back once. The dealer didn't like the price I got. They called me in to redo the deal. Basically they wanted $1500 more out of me. There claim was it was required for the note. It wasn't. We called the loan co. and all was fine. I left the car and keys with them and drove my trade in off the lot with a new tranny and battery for free that I didn't auth to be put in. I could have kept the car and walked out with it. But since they wanted to run a game on me I left them with a car that had 500 miles on it.