Update....12 Years Later.... and this is STILL, amazingly, the case. The PBI website is atrocious. There is no way to figure out through the airport's website or any of the rental car companies' sites that rental cars for the companies that say they are AT THE TERMINAL are actually 5 minute shuttle bus ride away. It is basically a lie. The counters in the terminal are almost never fully staffed and unless you are a member of one of the premium companies' elite clubs you usually have to take care of all business at the remote check-in counters.

Frankly, I've found that the rental companies out on Belevedere Rd (Alamo, Budget, etc) are much more convenient because when it comes time to return the car, there are gas stations right next to the drop off lots. If you are going to the lots inside the airport property, unless you put a gas station into your GPS so it takes you off the highway before you enter the airport property you will not drive past a gas station before you get to the drop off lot. The shuttle ride time for the lots on Belevedere is the same as for the lots inside the terminal.