I would absolutely rent a car. You can look into renting a car closer to the Wailea area, but what I have found is that for almost all travel, when you rent away from the airport, the daily rate is higher.

For example, when I was in Kauai, I was just going to rent from the Hertz at the hotel for a day, but the rate was 3 times higher than renting from the airport. Therefore, it was about the same price to just rent the car from the airport, and not drive it around very often versus renting the car from the hotel the one day that I needed it.

Plus, having it allowed me to go to the store to get some cheap drinks and snacks for the room.