Dito on Aloha Rent a Car. Once you navigate the web site and select your beast, its all good. We've used them twice and both times both vehicle and service were great.
First time around we rented a behemoth van, you could practically live in this thing. As Swoosh said, they pick you up from the airport and drop you back there on returning. They also kit you out with beach chairs, and brollys we as well as sand toys if you have kids. The big van also had racks built in inside for multiple boards.
The last time we went, the missus wanted a smaller vehicle, so we opted for a Chrylser Voyager (see photos). Van was great to drive and very comfortable, plus it easily fitted a board and gear with only one back seat folded down. This time we arrived in Maui late in the evening, but the guys had left the vehicle for us at the airport and keys were easy to get, so basically no dramas.
We are heading back again in June, and I have no hesitation booking with these guys again.