AC drain?
... although, most likely it isnt, since your floor is wet on both sides. I had a problem recently on my dII after running around with AC on, I've "discovered" the floor on PASSENGER side and rear seat floor area, same side, were all wet! I've been able to find an AC drain line, on the passenger side of the ****** opening, close to the firewall, underneath the truck - and it was clogged. It actually has some sort of a elbow type cap, my guess it is deisgned to keep any water from underneath the truck out, but still pass the water from AC out-- yet it was blocking it so the drainage from AC ended up inside the cabin! I poked around in that tube and having spilled like a litre of this water on myself i knew the drain was unclogged now. It now wroks just fine.
i hear some people have windshield leaks, so this may be an issue in this case.
good luck!