If you want to rent a car for a short period of time, here is the low-down. There are a few car rental places around the Prefecture in the bigger cities and even in the smaller regional towns (check out the yellow Town Pages pgs.843-6 for West Toyama and pgs.867-70 for East Toyama). It is quite easy to rent a car. All you need to do is to take along your International Drivers License, normal license, hanko and alien registration card. For a big van or 4WD ringing ahead of time is advisable. For regular white-plate cars then you can go down on the day. Twenty-four hour rental is from around 6,000 for a 1300cc car and 12,000 for 7-man vehicles. Below is a simple table with some of the prices for cars available from Toyota Rentals and Mazda Rentals. The prices vary quite a bit and are also seasonal.
TOYOTA RENTALS TOYAMA (トヨタレンタリース富山)
Booking Hotline: 0120-140-251
Takaoka Branches: 326 Higashi Kamizeki（東上関 326）Ph: 0766-21-01003-15, Kanayamachi (金屋町 3-15) Ph: 0766-29-1010
Tonami Branch: 5-45 Toya machi, (豊町 5-45) Ph: 0763-33-6100
Toyama Branch： 6-18 Honmachi (本町 6-18) Ph: 0764-32-0100
Uozu Branch: (本江1063) Ph:0765-23-0100
MAZDA RENTALS (MAZDA レンタリース)
Booking Hotline: 0120-175-656
Takaoka Branch: 415 Akasofu (赤祖父 415) Ph: 0766-24-8400
Toyama Branch: 1-4-48 Ushijima Honmachi (牛島本町1-4-48) Ph: 0764-432-1515
Toyama Airport: 30 Akigashima ( 秋ヶ島 30) Ph: 0764-95-3010
Club Tocoo does car rentals and hotel bookings…in English! They span many dealers across Japan, and are apparently pretty cheap. ALT recommended!