Bringing U.S. manufactured vehicles back to the United States after they have been exported isn't a difficult practice, from what I have been told by people that have done this. You have to have all the ownership papers in order, and the documentation of the previous owner, along with supporting documents, such as previous registrations. It is best to call ahead to the U.S. Customs at the border crossing to check for exactly what they will want to see in the way of paper work. The biggest stumbling block is to make sure that all the vehicle identification plates are still attached by the original method. If there is any evidence of tampering, then you will have a major problem, so it isn't worth the effort.
I have heard of some people making the deal, only if the seller is willing to deliver the car to the states. That is the best method, if the car is drivable, registered, and insured.
