I'm a bit late in finding this thread but I'll still present my warning.

If you drive the car short distances regularly (work close to home, whatever) then you should change the oil more frequently than those of us who drive 30 minutes or more to work.
When the engine is run and then shut off and allowed to cool, condensation forms inside the crank case. This is an unstoppable act of physics at work, especially in humid (read: most of Florida) climates. Cold starts also allow a little fuel to sneak past the piston rings. The condensation and fuel end up in the oil.
When you don't get the engine up to full operating temperature and keep it there for a reasonable amount of time, the condensation and fuel don't have time to heat up and evaporate. Shorter oil change intervals are required to keep the oil fresh and free of the ickies.
Driving the car for longer periods of time will help the bad stuff evaporate and be drawn out through the crank case evacuation system (modern PCV valve stuff).

Day to day driving with short hops and rush hour traffic are some of the hardest things you can do to a car. They're much happier when let loose on the freeways in open country.