I have some towels on the driver side back floor, I noticed it was soaked the other day, I reached down and discovered my rear floor drivers side was wet? I wonder what made the back floor wet? it'* just the drivers side I check the pass and it was fine.
Any water in the trunk, or spare tire well? If not, check the weatherstripping around the door, and also the water deflector inside the door. One way to check that is to run water along the window, then check for water leaking from the bottom inside of the door. Also check the headliner to see if there are any stains or wet spots. That could show that the drains for the sunroof may have come loose.
water is in the trunk definately, I would have more than likely noticed if driver side was bad by how many times I usually wash and or run it through the automatic washer. I knew some water was getting into the trunk (mostly just by opening it after every wash to get drying/detailing things) I'll more than likely go to the stealer this weekend to see what'* going on.
Before you head off to the dealer, you can check somethings yourself. Check all of the body seams that you can find to make certain that the sealing compound hasn't come loose. This is an old thread by PontiacDad about the trunk area water leaks, but is still accurate.
That thread mentions alot of really good potential sources but i didn't see the Seal mentioned. My spare tire well was full of water when i got the car and i found that the rubber seal was not sealed to the car at the bottom of the trunk opening. This is easily fixed with generous amounts of silicone RTV.