Working on this problem as well this weekend.

In addition to the wet rear passenger side carpet, I discovered that the front was wet, as well as the inside of the glove box.

If you open the sunroof and look down in the front corners, you'll see the little drain holes. I poured some water down into the holes and it drains out just in front of the front doors behind the wheels if the drains are clear.

To check the rear drains, open the rear hatch and look up on either side near the hinges. You'll see a black grommet on each side. Those are the drains for the rear of the sunroof. Close the sunroof and put it in "vent" mode and pour some water down into the back corners that way. You should be able to see water coming out of the rear drains at the hatch.

As it turns out, my drains are all clear, so the next step was to check the rear door vapor barrier. It was intact, but water was still migrating along the inside of the door panel. I have the optional side window sunshades, so I removed that and had my wife spray water while I looked inside. Sure enough, the seal around the fixed door glass is cracked and leaking and the water is running down that piece and down the door frame and into the car (anyone know which part #'s these are?).

I haven't tested it yet, but I'm pretty sure that the front leak was caused by a buildup of tree leaves and dirt that had collected in the front corners of the windshield and inside the air filter box under the hood. I vacuumed and cleaned all of that out and am confident that should resolve that issue.

Try the above and let us know what you find.

__________________
_________________
David

2005 4.4i Sport