I have read about water leaks in a 95 Grand AM. Soon as I read that my car started the leaking. Water builds up usually on the driver side floor board. NOBODY had an answer. Well , I found it. My last car leaked so I got pissed when this started happening. While it was pouring down rain I ripped up all the carpeting and sound dampener stuff, sure enough there was a small trickle of water coming through the fire wall. Very difficult to figure out where it was actually coming from. The Problem is actually a bad seal/waterproofing job when the cars were manufactured. I found the spot where it was leaking on the firewall, took everything off, and sprayed the hell out of it with rubberized undercoating. I also sprayed inside the firewall (not a fun or easy task). It still leaked. But the leaks were more defined. I hit it with a second coat yet to see the results. Later.

the seam right behind the Rack and pinion mounts is where they leak from, firewall, just to the driver's side of the center console.

Mine is acutally leaking in the vacinity right where the water drains out from the windsheild. There is a hole for the water to channel down onto the firewall. It leaks around the hole where the hood release cable goes trough the firewall and pretty much all around that area. It's almost like a membrane that's passing water through everywhere.