You are exempt from the Hawaii vehicle weight tax on one vehicle you own if you are a nonresident on active duty stationed in Hawaii, or a Hawaii resident on active duty or serving in a Hawaii National Guard or Reserve unit. In Honolulu and Hawaii County, nonresident service members are also exempt from the state registration fee, the highway beautification fee and the electric, hybrid and alternative fuel vehicle fee, and that exemption covers every vehicle they own.
Claim the exemption at your county motor vehicle registration office. Honolulu and Hawaii County use the CS-LMVR-50 form, and Kauai and Maui each publish their own nonresident military instructions.
Your orders showing you are stationed in Hawaii, your military ID, and your vehicle registration paperwork.