I spent seven years at Kadena AB. Take my advice... STORE IT!!!

Your car will be well on it's way to being a rust bucket by the time you come back and don't even think about getting it serviced, on or off base. If you do find a MB mechanic, the cost will be very expensive (the $ to ¥ exchange rate has been in the toilet since the 70's). Road tax (based on engine size), inspection and JCI (Japanese Compulsory Insurance) will put you in the poorhouse with an expensive car.

Most GI's and DOD employees buy used vehicles imported from the mainland. There are several used car lots that deal with Americans. A nice car in Okinawa is something you don't need, save it for when you come back or sell it before going over.

Here is a newcomer's guide to Okinawa put out by the Air Force that you may be interested in. Check out the sections on "Automobiles" and "Driving on Okinawa". They will answer most, if not all of your questions: http://www.kadena.af.mil/newcomers.htm

Enjoy your stint on the "Rock"... (69 miles long and 14 miles at it's widest point, average speed 40 kph AND humid).