My husband and I will be visiting Kauai and Hawaii in April. Last time I was in Hawaii, I spent all my time on Maui. We are taking vacation in advance of a meeting to experience the natural beauty and history rather than nightlife, dining, or shopping.

I thought this time, since we have to change planes HNL anyway, that we will take an early flight from LIH on a Saturday, book tickets for Pearl Harbor tour, maybe go to Palace or Museum, Punchbowl.

My decision is whether to rent a car, put our limited luggage in the trunk, do our touring, and fly on to KOA at 6 or 7pm that evening, and spend the night near KOA.
Or overnight on Oahu, I guess in Waikiki (which doesn't interest us, but the airport hotels get really bad reviews), and fly out at 7 or 8 am the next morning, heading on to Volcanoes National Park (too expensive drop charges on auto to fly into Hilo and out of KOA from where we head back to mainland).

If we only do the day in HNL, then we have all the stuff in our trunk, but we get an earlier start the next day on Hawaii.
If we stay overnight HNL, we won't be able to check into hotel when we arrive at 7am, so still either carry luggage in trunk or else spend an hour driving to hotel, asking to hold luggage, then back to Pearl Harbor. Plus we get a later start on Hawaii the next day. But we have the flexibility to visit whatever we want without as much time pressure.

I don't really like the idea of all our stuff in the trunk while at Pearl Harbor or museum (will have an iPad and notebook computer). Saw Aloha Airport Delivery will hold bags for $20 for the day (no lockers at airport).

Has anyone just visited Honolulu for the day in transit?
Any suggestions?