I specifically said while I was negotiating on our most recent vehicle, subject to approval from the wife, approval for the final trade in value. They could definitely not lock in any deal without the VIN, AND the car in their possession, even though the car was coming from another dealership that the owner.. owned.. they said it had to be physically here, inspected, and approved by me before we continued paperwork. I still had plenty of chance to re-negotiate, which I did.
Again, when they asked me to put $500 down to "lock the deal down" I still said, look, if my wife doesn't like the car, or I still do not like the trade in, then I'm not taking it. He gave me initial numbers based upon a theoretical trade in of my car, since I assured them it was pristine and had xxx miles. They actually even said "your car is really only worth 18.5 but we'll honor 19.5 like we assumed" when it came close to the end, I said honestly 19.5 is too low, and every other place I was looking at with the competing cars told me they could give me at least 20 so I wouldn't settle for less.
Long story short, I guess it's all in the wording, they only made me and the manager sign a paper, but it did say all those "conditions" and then they found the car. So hell no would they be able to keep my money, I would call a dispute on my cc company and I'm sure lots of shit would hit the fan for the dealer "holding people hostage" when there were no final papers signed.