Most of the American Cars have been scrapped since Reversion to Japan 1975, since left hand driving cars were a little bit harder to drive on the left-hand side of the road and shipping of American Cars were nearly prohibited. Nothing could be shipped newer than a 1973 American car in 1988.
There are some American cars still owned by the local nationals, from the 1980's and 1970's, to include Buick and Lincoln Continental's. Two were near my wife's village in Ginoza, which has a small museum, but no cars as of 1988. Near Our Sanshin Sensei's residence in Okinawa City, we both saw an excellent looking 1970 Datsun Bluebird in 2006, and I also saw an immaculate Nisan Cedric near Gate 3, KAB in mid 1980's. Both of these cars were well taken care of by their owners, the Bluebird was actually having maintenance completed on it, when we were searching for our Sensei's residence.
Okinawa's love automobiles so I am sure there is interest among them to start a museum, or at least place a few cars in existing museums. Cars did not become important to the people until the early 1970's. They simply could not afford them because of the luxury taxes they paid on the cars and the price of petrol.
My brother-in-law had a motorcycle up until 1971; yet he had a very decent job - family needs come first. Americans and Okinawa's need to have car rally's and meets together in order to encourage the restoring of antiques and classics. It took a while for American to get started - a Lincoln Car just opened two years ago in Michigan to encourage the restoration of the Lincoln and Lincoln Zephyr motor cars.