Don't leave your luggage (or packages, etc.) in a rental car unattended. Go to your next hotel and leave your luggage with the bellman if your room isn't ready. And geez, it's HOT in that trunk!

(Besides, you don't want to be worrying instead of having fun!)

Pearl Harbor ... they have an area where you can check stuff (with an attendant). And most folks stuff their pockets with their valuables ... or leave them in the hotel room safe. Cargo pants are great!

The problem isn't any different than any tourist areas in the US. Give a jerk an opportunity and they'll take advantage of it. Will you have a problem if you put your luggage in the trunk and not get into it with others around? Probably not. I've had all kinds of stuff in my car on Oahu and didn't have any problems. Who knows if you will be as fortunate!!

There was a problem with things getting stolen out of cars in the Pearl Harbor National Memorial parking lot and it's patrolled by security!!

I remember a post from visitors who parked at Ala Moana (in the underground portion near Foodland, IIRC), and came back to find their trunk popped and all their luggage gone, 100% of their belongings gone, including things they had shopped for to take home.

I think Oahu is quite bad for theft.

I moved to Hawaii from Oakland, so no stranger to vehicle crime, but Hawaii has so many rental cars, a never ending source of easy pickings for addicts with daily ice habits they need subsidized.

There are always problem areas, which is not to say there are absolutely safe areas. Gated neighborhoods and parking lots with security, and good hotels... other than that, watch your car.

I spent one day sightseeing on Hawaii with all the stuff in the car, and we did not leave the car unattended. We saw numerous guys eyeing the car with that familiar look of unwarranted interest.

My advice is not so easy to follow, but I would fix your itinerary. Transition days with all your stuff, combined with a bunch of sightseeing, are a mistake. Fix it.

Thieves can tell which cars are rentals ...

Not only can they tell rentals, but they know the ones that are easier to break into. There was a fuss a few years back when it turns out the agencies knew a certain model was beyond easy and the most stolen car in America, but Honolulu was still renting loads of them without so much as a caution.

Yep to the above advice.

For those who think renting an older car or one through turo will help---it doesn't.

PS. my reply #4 is confusing where ai said I spent one day in Hawaii sightseeing with stuff in the car. The word was Oahu, not Hawaii. Actually it was two transition days, because we went to the North Shore from Waikiki and spent a night before flying home, so two days of a loaded car. We watched it vigilantly.

It was far from ideal and relaxing, and I would do it differently if given another chance.

The bottom line is you don't need to keep anything in your vehicle at all if possible! That applies to 48 Mainland states and Alaska & Hawaii. :)

But when transiting across an island to a new lodgings, there’s no avoiding it. What can be avoided is believing you can sightsee all the way just as carefree as when you don’t have the stuff.

In regards to the original question — hiking trail parking is bad because they know everyone is going out of sight of the vehicle for some time. Any place that is lonely too. Beach parking ...

Sometimes the thieves work in teams with walk-in-talkies (or whatever they want to talk on), using a lookout. The lookout might be behind something watching people park, and watching people leave and on the watch for them to return, while the other guy does the break-in. So you never open your trunk after parking, can’t let them see what’s in it. But they still assume most cars have stuff in the trunk.