Well, I have spoken to various folks at WDW, at the resort level and the vast majority of them have told me that it would have to be pretty flagrant to have a car towed. Are cars towed from resort parking lots?? Possibly. But in all reality, what happens to the guest, at lets say BLT, that has parked his car in the lot, as he is entitled to do, but he forgets to put his parking pass on his dashboard. He figures he'll bring it down with him the next morning, but in all the excitement of hitting the parks, he forgets.
So..now this car has been parked there, for a very long period without any identifying paper on the dash. Is this car now going to be towed??? Hope not.
I just don't think towing of cars happens enough to worry about. Now, if when you said 'parked properly' you meant that the car was parked sideways, taking up three spots rather than head in, using just one space, then sure...you may quite possibly get towed....