I would just like to add my recomendation for Island Cars. We have been using them now for several years and have had an excellent service. We have just returmed from Punta Prima and a couple of weeks before we left we decided that we wanted to hire a 7 seater car for 3 days. Island Cars got us a car and delivered it to our hotel at a quite reasonable price €218.
A few of us have also have been away in September over the past few years and they again deliver 2 cars to our hotel on time and we have always found their prices very reasonable and the quality of cars good.
They always answer emails and offer a great local friendly service, and you only pay for the petrol you use, given the car with a full tank and return it with a full tank.