I live in the humid hell they call Florida too , so I know and feel your pain, and have felt it for 10 long years....blah..(I live in Hudson., go to school in Tampa)
do you really notice a difference when driving though?
like lets say you're cruising at 2500 in 5th, and turn the a/c off/ondoes the car jump or no big difference?
at idle, I notice a difference if it is off or onbut once I am actually driving.. I barely notice the difference
so, of course I always drive with it on, and the windows up
-Dan