If u plan on staying at the hotel and beach lounging for the whole time,then a car isn't necessary. If u want to get to downtown to the restaurants,clubs,etc then a car would be a good idea cause the Westin and good hotels are 30 minutes from the airport and 30 minutes from downtown.....basically half way between the two. Those rates at the Westin look GREAT with the F&B credit and free 4th night. When I went to Cabo last Sept of Labor day weekend,there was a hugh hurricane warning and high winds that grounded all flights for a day and it was horrible so keep in mind MEX has hurrican season in Sept.