we are doing the same cruise on may 29th and my wife did all the research, carnival shuttles , private shuttles and limo rides were all much more exspensive than renting an Avis car. we are going to fly in the day before stay at the radison on the beach in port canaveral then here is the great part the rental return in one block from the hotel and they provide a free shuttle to the dock. This way you can have a car the whole day you are there and wont be stuck to walking. the rental was around 4o dollars unlimited milage for the day and you cvan pick the car up right at the orlando airport. going back we are taking the carnival shuttle to the airport.