I always rent motorbikes of some type in Hawaii - it is by-far the easiest way to get around and park. You can basically park anywhere. This week, I rented a KTM 390 Duke - it's an amazing 'naked' road bike that only weighs 325 lbs. Certainly gives you quite a thrill taking it through the streets of Waikiki and up the 'Gold Coast'.

Streets of Waikiki:

Up the Gold Coast: