You might want to sign up for Dollar's FastLane. It's free (or was when I signed up). You have to sign up by mail, because they need a signature, so it does take some time. They take a profile, and you get to go into a special, presumably shorter line at the counter. Since you've already told them your insurance and gas preferences, your form should be ready to go. I haven't tried this at MCO yet, but when I went to Denver last month it was great. A sign at the counter told me to go directly to the shuttle bus, the bus driver radioed ahead that I was coming, he dropped me off first, by the car, and a rep met me at the car with the contract ready to sign. It was by far the fastest I have ever gotten a rental car.
Has anybody done this at MCO?