Did it all online. I would book the car then register for Dollar Express which cost nothing. Only in this way can you skip the sometimes super long line at the rent-a-car center. While I was at it I would also apply on line for Alamo "Insiders" same reason. Last thing I want to do when we touch down is wait on line for an hour. When you check again and find a cheaper rate you can book and then cancel your original, I know people who have done this many many times for the same reservation, no penalty. Some click on "change reservation" but this in itself may not give you the cheaper price so I just make a totally different reservation then cancel afterwards.