Update...After finding 1.5 inches of water on the passenger side, I knew I had to investigate further. I read on the forum that the weather stripping under the cowl tends to dislodge allowing water to enter through the blower motor housing. This was exactly my problem. Sadly, I had to replace my blower motor (OEM $59.00) and installed a water deflector part# 15794785, which I ordered from GM ($4.00). You have to modify the cowl for deflector to fit. This will resolve any other potential problems associated with water entering through the blower motor cavity. You will also want to replace your retainer pins (part #10053182, $0.48)...you need three retainer pins. I removed my cowl, which was a one-piece unit. I removed the wiper arms, which was easy enough to access my cowl. I found it more convenient to work on modification using my workbench, rather than struggling with it while still attached to the car. I also installed a new 3M foam weather stripping on my cowl. It was a bit more work to remove the old one along with its glue residue. Overall, I am really happy with the fix.
