I replaced the firewall seal this weekend. What a b*tch of a job! The old foam seal looked a little stretched around the drain tube, so I could see water getting back inside the car through there. The new one is a much tighter fit, and I smeared some RTV around the tube where the foam seal presses against it, as well as around the perimeter where the seal contacts the firewall and where it meets up with the plastic drip tray. As soon as we get a little humidity around here, I'll be able to tell for sure, but I'm fairly convinced that it's tight again.
