I'm NOT a lawyer. However, I'd suggest that you have a skilled contract lawyer look over the contract.
You have to decide, will it cost you more to have the contract reviewed by a lawyer, than keeping the vehicle (with the problem) will cost you.
Their may be other items in the contract that are "Not in the public good" that may allow you to void the contract. Just because it's in the contract does NOT make it legal. If they charged you higher than the legal interest rates, left out items like your right to cancel a deal within a certain time period as required in some states, on major purchases, even if it was NOT bought at your home, then you might have an out.
Any unclear parts of the contract are usually ruled in favor of the party that did NOT have the contract prepared.
Unfortunately, contracts and insurance policies are USUALLY written by lawyers and are usually 100% legal, although they may be ethically or morally wrong.
The law is legal, NOT logical. BEWARE of mediation which may favor the business owner.