Last but not least, make sure you reserve your car rental before arriving in Kona. I know someon

An independent rental one way air ticket car company named Harper, rents 4wheel drives and motor homes. They used to be located right there at the airport. Not anymore, now they re about a mile or so away. I ve rented trucks from them before and they definitely don t come under the cheap rental car concept.
This only works if there are 2 or more in your party. One of you gets on the shuttle one way air ticket to the rental car agency and the other person goes and waits for the luggage at baggage claim. Then the person with the luggage s waits out at the curb for the other person to pull up with the rental car to load the luggage.
It depends if you re a back roads adventurer or not. If you are, rent a  4 wheel drive. one way air ticket  You ll need it for some of the more secluded places one way air ticket on the island. Like  Waipio Valley  for example. You can not drive a 2 wheel drive car down into the valley. The road is super steep and you need the 4 wheel drive to get back up the road.  Most rental companies don t allow you to take their vehicle off-road or to Mauna Kea and Wiapio Valley.
If you violate the terms of your rental agreement and the vehicle breaksdown in one of those locations, you re screwed. Hope you have about an extra $1000 to pay the tow company. Oh yes, you re paying baby. You were specifically told in writing when you signed the contract. Remember? If you re not into getting off the beaten path, then just rent a car.
I see a lot of folks driving around in convertible rental cars, their great in the winter. But I wouldn t be driving around in the summer with the top down, unless of course you have a desire for major sunburn.
Last but not least,  make sure you reserve  your car rental  before  arriving in Kona. I know someone who works at one of the rental car agencies that told me people call after they get off the plane looking for a car to rent and guess what? Sometimes they re out of cars! This is not the big city folks. Plan ahead or you may not get a rental car. Really.  And whatever you do, don t rent from Alamo. On the mainland they re OK. But we re not in Kansas anymore