There is limited useful online information about this topic. Here are two forums on Okinawa Hai.
http://www.okinawahai.com/my_weblog/2007/04/options-for-you.html
http://www.okinawahai.com/my_weblog/2008/04/faa-approved-se.html
Our experience with the options:
1. Parking at Naha airport
The fees have been restructured and it now costs 1000Y per day. Brochures regarding parking at the airport are available at the information desk in the terminal. There is covered parking. This is a highly convenient option, and for a shorter trip it makes financial sense.
2. Kinser
The military does not do a good job facilitating the use of Kinser for airport parking. If you arrive and leave on a weekday during daytime or early evening hours, then Gate 1 should be open and you can park just inside the gate and catch a taxi. The gate guard can call one, or you can hail a taxi from across the street. The taxi costs approx 18-2500Y unless you hit bad traffic. Obviously, this means the Kinser option is only economical if your trip will last >6 days, meets the above conditions, and you don't mind the hassle. If you leave on a weekend, holiday, or have late or early flight times, then it is a terrible option because there is no convenient parking near the north gate (by the Pizza Inn) and if your car is at Gate 1 there is no easy way to get back to it.
3. If you have TAD/TDY orders, then park at the Naha Port Army base (on the right heading south on the 58 as the road funnels to the airport). Leave a few minutes spare to fill out the paperwork (you need your car registration info, military ID, and orders) and then take the permit to your car. When you leave, return the permit to the office. The gate is open 24/7. The taxi ride to/from the airport is less than 1000Y.
4. There is a place called Sky Parking, but unfortunately we have not figured out where it is. One of the blogs reports they charge 4500Y/week. There is a mud map on an advertisement hanging on the wall at the Naha Port office.
5. Shuttles from Westpac Inn and Shogun Inn. The Westpac charges 10$ pp.
http://kadenaservices.com/shogun/shuttlesched.html
http://www.mccsokinawa.com/lodging/index.asp?lodge=5
