First I would read what ever you signed when you made the deposit. It should stipulate the conditions under which the deposit can be held. Usually they are for a set period to back out and almost never for a condition discovered later. Also know that you could make a claim in a Small Claims Court. I don't think you will win. I've been there on a boat for similar reasons and it's like the judge didn't even read what I submitted or listened to what I had to say. He just ruled that the deposit belonged to the seller. Next case!
You are smart to NOT proceed with the deal. An RV is about fun. Not a headache and that is a BIG headache. You could protest out in front of his dealership, this being America, free speech and all. Might get you something from him just to go away.
My guess is that you probably were going to pay too much anyways and this is a good excuse on your part to back away. What was your deal price anyways?
