I've been hunting for this for a year now. Drivers floor floods every time it rains. Soaks the transmission tunnel foam sound deadener near the floor under the center console, then the floor. A/C drain tube is good. Found a factory hole today with water witness marks, just above the the dash bracket bolt. Definitely the guilty party. Where does the hole go, and how does the water get behind it?

brake, gas, dash bracket for perspective:



wet hole above dash bracket bolt (a/c vent tube visible):



there's obviously another layer of sheet metal behind the hole, so yet another body seam filling up with water from unknown ingress. No factory attempt to rubber plug the hole, unless the new for 93 body with "X percent" fewer body panels was still a mystery to assembly line welders. Anybody here know if the dash bolt pokes through the floor into the transmission tunnel or dead ends inside the floorpan?

 

Does anybody have street side photos of the firewall and transmission tunnel with engine/trans removed? I have yet to see a stripped 93-94 shell and mine ain't coming apart before the rains start big time in a week or two.

 

I could image the firewall or a-pillar is rusted through, on the late models this is a common issue. Did you check the firewall seam from within the engine bay?