ya, freaking sux. i never know if i'm going to have a job the next day so i'm to scared to spend $140.00 on the windshield when the duct tape works. it looks bad.

 

I had the same problem, and found out that the drainage lines were clogged with leaves and dirt. Debris came through the grates under the front windshield and clogged up the lines. Water would back up through the firewall and into the exact location you mentioned. I stuck a wire hanger up through the split in the chassis where the water is supposed to drain through. I cleaned out the passage ways and tested by filling the grates with water. When the lines were cleared, the water flowed through normally and didnt back up and spill over into the passenger seat. Dont know if you still have the problem, but if so, hope this helps!

 

push out on windshield, mine was very loose

 

('93 240)Windshields aren't the only source of water getting to the front passenger floor. I found the floorboard itself had rusted around the plug under the car. The water was coming in from driving in the rain.I pulled up the carpet and sealed the leak from the inside with FLEX TAPE (as seen on TV). Problem solved for now.