Parking in Hawaii you will be different on each island and sometimes very different from area to area around the island. Parking is normally not even an issue in places considered more ‘country’ like all of Lanai and Molokai and a lot of Kauai and the Big Island. Oahu and Maui, however, can be veritable traffic and parking nightmares.
On Oahu, parking issues will be different depending on where you are around the island. Inside Waikiki and Honolulu areas it will be difficult to find parking spaces. There are public lots and public garages that you can pay to park in. Many hotels do have public garages and will charge you $7-$15 a day to use them. $7 is the cheapest I have heard of, and that’s at the Resortquest at the Waikiki Banyan Hotel (2005).
Outside of Waikiki and Honolulu, parking gets a bit easier. Oahu’s North Shore towns usually have ample parking areas lots and areas. Kailua can be pretty packed, but other Windward areas are quieter and have lots of parking. Most beach and attraction parking is free or quite inexpensive but the smaller lots do tend to fill up (like Hanauma Bay parking lot – it’s huge but completely full by 10 am) and you may have to circle around until somebody leaves.
Parking on the Big Island varies widely depending on where you are. Parking in Hilo and Puna and Kau and Hamakua is easy as pie. Waimea is where it starts to get hairy, and Kona is a lost cause. Just about every hotel in Kona now charges for guests to park in their lots. There are a few paid lots with decent prices right in town. Kahaluu Beach is a very popular beach right on the main drag in Kona, with a very small parking area. If you don’t get there early you’ll have to park right on tiny Alii Drive or look for parking in the residential area. I don’t know what they were thinking when they planned the streets in Kona.
As for Maui, well like the traffic, parking in the country areas (Upcountry, Hana) is a delight, while parking spots everywhere else are few and far between. Hotel areas like Wailea and Kaanapali are easiest, as they all have parking garages. Hardest is probably Kihei, where a large population is trying to live and work and another large population is trying to shop and surf and sightsee, but there are no real planned parking areas.