I know this is a common issue that has been discussed before. I have had the ongoing issues with the leaking sunroof leaking into my h3. I pulled the tubes cleaned them out and drilled out the rubber at the end of the grommet. That stopped it from leaking into my onstar mic. Then the water started to leak from the firewall where the tubes drain. Today I was washing my hummer and saw some pine needles sticking out from the rubber trim at the top of the windshield. I ended up taking it all off and the side trim, all of the drainage around the windshield was backed up with leaves, dirt, and pine needles. Then once I figured out where it was draining, I found another issue. The genius GM engineers designed the vehicle to drain right next to the air intakes on both sides of the windshield. I took off the air intakes covers to find the space loaded with dirt, leaves, and pine needles. I cleaned everything out with water and air, I should be getting more air into the engine now lmao. Anyone having this issue should pull all the trim and covers off ad clean it. Careful taking off the top trim piece, Its difficult to get back on, run it under hot water for a better fit before putting it back on.