You dont really need a car to go around the island. You can rent a scooter, or bikes or do a tour. Renting a car is pricey especially if you want a 4x4 jeep. You are looking at 90 to 100 dollars for 24 hours.
We didnt rent it for the whole time we were there. We only got it for a 24 hour period and for us, that was enough. We had seen everything we wanted to see. We drove at our leisure around the entire island, found some nice beaches and searched for waterfalls.
I love the sense of freedom of renting our own car and going where ever we want. On the downside besides the price is that at our hotel there wasnt enough parking for everyones car.
One of the best ways to discover the island is to rent a car.
The tour of Moorea (60km) can be done in less than one day but if you go up to the Belvedere and decide to visit some other spot, it might take a little more time.
We decided to rent a small car for 2 days, inspite of the price. There is actually no real bus connection on Moorea and we didn't want to go by taxi, so...
We found a Europcar and an Avis office in Papetoai, near our hotel and the group of shops called "Le Petit Village" (PK 26.3).
We rented a car from Albert's Rent-A-Car, located directly across the street from our resort. We intended to only rent the car for 8 hours, but when we insisted that we didn't want it for longer, the attendant gave us 24 hours for only 500 CFP more (about $7). It turns out that we needed the car for the full day. Even though Moorea is not very big, only about 30 km around, the roads are all very winding, and the speed limit is 60 kmph (about 45 mph), so it takes longer than you would think. Plus, there are so many things to stop and see! There are shops along the road to buy souvenirs cheaper than at the airport or hotel gift shops, roadside fruit stands, scenic overlooks, many pearl shops, and even internet posts located all around the island.
I would not recommend the scooters for use traveling around the island. There don't seem to be many driving laws on the island, and locals pass with little care for who/what may be coming at them (we actually passed in between two cars going opposite directions while being transported to our restaurant one evening). We also met another couple at our resort who had rented a car, and the young man was all bandaged down one side of his body. They had rented scooters, and he was going to fast for a curve, couldn't make the turn and had to bail from his scooter or run head-on into a car coming the other way. We were told by one of our tour guides that there are less than ten police officers on the island, and he said that most locals felt that was too many. :) Just keep that in mind...
Whilst it is not especially cheap to rent a car in Moorea, it can work out quite cost effective compared to paying someone else to take you to places (hotels are so expensive you don't tend to be staying long, so everything is done in a hurry, so Le Truck is not always feasible!).
You can rent cars by the day with unlimited mileage however bear in mind that Moorea is very small, so unless you planning on driving laps of the Island all day, you are unlikely to do big mileage!
Probably the best bet is to rent a car for a couple of days and try and do all your daytime excursions and evening trips whilst you have it. Then spend the rest of the time exploring your local beach. For instance if you are going to an evening performance at the Tiki Village, they can want almost $20 USD per person to pick them up (even if you are only staying a few kilometres away), this pays for about half the car and you get all day use of it too...
This picture shows the car we rented at Titiroa Marae, the wall at the end of the carpark is the Marae, not a carpark wall at all!
The island is small but taxis very expensive and public transport lacking, so definitely I would not stay on Moorea without renting a car if you want to see more than just the beach where you are staying. Every hotel can arrange car rental or you could even make arrangements before you arrive. The island is only about 40 miles around, so quite easy to circumnavigate it in a day.