At the recommendation of several of you on this board, and due to the lack of carts from other providers, my brothers rented a cart from Island Tours for the week they were with us in SP. In a 24 hour span, they had four different carts. One couldn't get out of it's own way, one backfired constantly, one was very "iffy" as to it's mechanical soundness. Finally, they got one that was very loud, like it had bearings that were bad, but it managed to get them where they needed to go. Unfortunately, it developed a flat tire after a few days, and they had to take it back, making them getting a fifth cart. I would dare say they spent no less than 4 or 5 hours in all at the rental office getting these things resolved. Although they were anxious to make it right, and tried to be helpful, it still remains that in a weeks time, five carts were required, and each cart meant a trip back to their office. Not very good when the place they are staying was across the cut, making each trip a ten dollar Belize trip.
Just something to think about, if you are considering renting from them.