Good afternoon. I am Loren, a licensed attorney, and I look forward to assisting you.I am sorry to hear of your dilemma. I realize how frustrating this is for you and I hope to provide you information which is accurate and useful, even though it may not be the news you were hoping to get.
Unless the contract provides a right of termination, it is enforceable. If your wife has not signed then it is only enforceable against you.
However, if you have not signed the finance papers or paid anything the dealer may, after a bit of pushback, allow you to walk if you ask and are adamant.
While you would be in breach of contract, the dealer is in the business of selling vehicles, not suing potential customers and they will just sell it to the next customer who is looking for a camper.
In such a case, if the sale price to the subsequent customer is at least as much as your contract price, the dealer then has no damages to sue for.
Your next step is to let the dealer know that you are backing out. Be prepared for pushback, but you can probably negotiate an out.