i Fixed this problem in my 90 teg. the previous owner of my car did some wierd ceiling on top of were the actual seal of the windshield should be. i notice3d as it started to rain, the passenger sides feet leaked and created puddles. i popped the hood and noticed right were the hood is bolted on, there is a black plastic piece on either end under the windshield. My friend told me to get a water hose and spray on either corner to see if thats were the leak is coming from. sure enouch it was. just to confirm this, i took the time to take out the glove box, and i saw the air conditioner system. i looked underneath the plastic peice wich is under the glove box, and i noticed that there was a hole in the metal bottom of the ac fan. The metal bottom looks just like a metal sheet. next to the metal sheet is were the water drains through a tube, but the water was not draining through the tube because of the hole. i got rtv silicone and i sealed the plastic pieces up and sure enough the leaking stopped. now to go to a junk yard and replace that metal pan