Hi Micksgirl!!!
We have used rental cars several times for our cruise. The most cost efficient way to do it is to do two on-ways rentals. The first one way would be to pick up the car at the airport in Orlando. Keep it for use at WDW and drive to the port either the night before or the morning of the cruise. If you check out this link it will list rental car information in Cocoa Beach. We always use
Avis and Budget as they seem to have the best rates.
Then, make another one-way rental for the morning you get off the ship. Avis and Budget both have shuttles that will take you from the ship area to the rental location to pick up your car. then you just enjoy the car for the day and drop it off back at Orlando airport before your flight.
We always use codes that we find at
www.mousesavers.com for rental from Avis and Budget and book at their website.
Here is the link for info on what rental car companies are in the Cocoa Beach area
http://www.dcltribute.com/carhire/
Here is the link to rental car codes that can be used online.
http://www.mousesavers.com/rentalcar.html
Both sites have tons of info on getting the best rate for rooms at WDW and rental cars....check them out.
Many people, including myself, like staying at the port area the night before the cruise. This way there is less rushing the morning of the cruise. We usually stay at the Radisson because it is the closet to the port (about 2 miles or so) and it has a shuttle to take you to the ship. So, you would drop off your rental either the night before the cruise or the morning of the cruise if you wanted to go to get breakfast and then take the hotel shuttle to the ship.
Hope this helps.
MJ