The question is occasionally asked about where to get a shower when on a long layover at HNL. I've got a 12-hour layover coming up, connecting from Japan to mainland US. I plan to rent a car for the day and drive around the island, which I've done before. But this time I'd like to get a shower in, including a bit of soap and shampoo (of course in a bathing suit if at the beach).

Has anyone here actually done this? If so, do you have a park you recommend? I'm a bit concerned about leaving my stuff unattended in the car while parked at a beach.