I would never buy a used car without looking at a CARFAX report FIRST!
However, I do smell fraud here because I have NEVER seen or heard of a dealership that did not pull a carfax on any premium priced used car.
It is standard procedure. They all do it.
You could sue them for the misrepresentation, and in the process you could subpoena CARFAX to see if that dealership pulled a CARFAX on your vehicle.
Very easy to do.
You can also file a "diminished value" claim for the misrepresentation on the dealership's "errors and omissions" insurance policy, commonly referred to as E&O.
The State of Florida Department of Agriculture and Consumer Services licenses and regulates auto dealers. File a complaint with them, and also request bonding and insurance contact info. You can get this through the dealer services side of the DMV here in FL, as it is public record under consumer protection laws.
You have a valid complaint regardless of what Jim says!