If you plan to spend the majority of your vacation in Puerto Morelos, you do not need a car. The houses are within walking distance of all restaurants and stores in town. The cab fare to/from town is about $2.00. There is a phone in the house that calls the cab stand directly. Day trips to Tulum, Playa, etc. can be arranged through a transportation service. If you plan to travel extensively while you are there, it would be a good idea to have your own vehicle.