I bought a car here rather than shipping. It was just easier. My neighbour, however, just shipped his car here from SF. When I asked him about it, he said:
From Oakland port, it's $1500 by Matson or $1450 by Pasha. We tried to book with Matson but they couldn't get our car here by 1st week of January, so we booked Pasha. Our car arrived the day before we landed and was ready to pickup the day after. Takes 2 days to offload and have ready for pickup. Depending on time of the year, could take 10 to 20 days. Actual voyage is 5 days. One has to register their car with Hawaii within 30 days of arrival. HI DMV checks the bill of lading to make sure you do it. Also, cars operating in HI must have a safety check sticker on the back of their car and must be renewed annually. You can keep your CA plates but HI will issue you rainbow plates. I don't know what the consequence will be for not obtaining a operating registration with HI DMV... but not having the safety check sticker is a violation. Shops won't issue us a safety check sticker unless we have HI plates.