M.L.
I had a friend buy a car through ebay... it was a rare classic that he had towed cross country for, that he gutted and rebuilt ,so to him, working condition didn't matter.
Really, I don't know how it works, you would have to get the car to Florida to have your mechanic look at it... probably better to have a mechanic there check it out... as I don't know if driving it over state lines will protect you from returning it should you not like what your mechanic says, or if the car will break down on your way back.
Ebay does have a car buying guide though here, so it could be helpful for you, as well as another great ebay car buying tips:
http://reviews.ebay.com/BUYING-A-CAR-ON-EBAY-NECESSARY-FA...
http://www.doughroller.net/personal-finance/how-to-buy-ca...
This advice is particularly helpful:
Before you bid, make sure you have an out: Bid only on auctions where sellers allow you to cancel after you inspect the car.