You can rent dune buggys at Costa Maya. If you go outside the shopping area where the buses and taxis are there is a stand there that rents them (as well as the golf carts). As I recall the Dune Buggys were $30/hour. The golf carts were $15/hr. You can also take a taxi to Mahahual. We opted for the golf cart as we wanted to go further down the road past Mahahual and just look around. While some people walked, I wouldn't want to. Its about 2 miles and it was very hot while we were there. I pretty active but that wan't my idea of fun.