I second Monica's suggestion to find a hotel with an airport shuttle, then take the shuttle back to the airport the next AM to pick up your car. The shuttles run on a regular schedule in the AM's and the ride back to the airport is just 2 or 3 minutes...I have tried several times to work out a rental car pick up at one of the hotels, but it has always wounnd up being significantly more expensive than just renting at the airport... plus if you rent at the airport then you have the added convience of easy drop off on your way out of town. I have seen posts from people that got much better rates from rentals at the hotels or WDW locations, but I have never been able to get even a comparable rate.
We always seem to wind up getting a late flight into Orlando...and over time we have figured out the easiest thing for us is to get a 3* hotel room through Priceline ($40 or less). We have stayed that way at the Marriott, Rennaisance, Holiday Inn Select and the Hyatt in the airport...all were very nice. We have never had to wait long on the shuttle when we got there, and the longest I think I ever spent getting the car the next AM was 45 minutes or so (and that was because there was a long line at the rental counter...on our last trip it was less than 30 minutes from the time I left the room at the Holiday Inn Select until I pulled back into the parking lot with the rental car!!)
We also really like the Embassy Suites at the airport (runs more than a Pricline room) if we are going to have more time to spend at the hotel and/or time to take advantage of the nice breakfast we sometimes stay there. They have good shuttle service too.
Have fun!!