Tim, bad luck on the motor but I would consult an attorney about taking this to small claims court in Lafayette. If your judgement holds up, the dealership will have to make it right. Judgements will totally wreck the dealerships ability to continue their finance program and most of them are on finance programs for their inventory. It will be in their best interest to take care of this before it gets to small claims court. My second course of action would be to visit some local dealers and find out if it is customary to inform buyers of used equipment about any modifications the equipment.
Under the Full Faith and Credit Clause of the Constitution, a judgment by a state court must be fully recognized and respected by every other state. For example, suppose the prevailing party in a California case knows that the defendant has assets in Arizona that could be used to pay the judgment. The prevailing party may docket the California judgment in the Arizona county court where the defendant's property is located. With the judgment now in effect in Arizona, the prevailing party may obtain a writ of execution that will authorize the sheriff in that Arizona county to seize the property to satisfy the judgment.