lovetotravel,
You may have some difficulty finding a car service that will pick you up early. I've called a number of them trying to get a 9:00 pickup and they are telling me that because they are picking people up from port and taking them to the airport, they won't do a pickup before 10 or 10:30. Still looking...
i'm having the same problem. i thought it would be easy but not so much. i had never thought about them having to pick up at the ship first so it came as a shock to me. not sure i want the bother of the rental car option though. i think i'll just be happy being there for lunch .