Driver's floor pan water leak problem
 

Last year, I discovered that I had a leak problem where the driver's floor area is. Obviously too lazy post about it because it only happens whenever there is heavy rain. During the past winter the floor was always wet there because of having a mat there, plus the snow that I dragged in with my boots. I figured it was just something that would dry up. Skipping ahead toward this past summer, it never dried. I had to cut open the rug to allow it to air dry.

Things I do know: No roof leak, no leak anywhere else. I doubt there are any holes in the floor board/pan. It doesn't make sense. It's just that one spot. No trails leading from the firewall area.

What I can guess it may be: When I took off the plastic trim windshield wiper/cowl piece to paint it, I ripped off the weather seal that sits on the glass to prevent water from dripping into the firewall space. Although usually water travels through it to the ground? Reason for, is that it is very thin, and a burden to put back on. So there is a gap. Anyways I don't know if there is a random canal that is getting water from the outside and traveling toward the pan. But like I said there is no sign of water trails leading to that spot. This has happened several times.

https://cimg9.ibsrv.net/gimg/maxima....95cc3ff447.jpg
https://cimg0.ibsrv.net/gimg/maxima....49b668d26a.jpg

Got a sunroof? Check the drain tubes.

+1. Got the same problem a while back. Turned out to be too much dirt behind the driver side mud flap (which is a plastic piece held by too bolts on the rear side of the wheel well)

My apologies I forgot to mention that I have NO sunroof. I don't have mudflaps at all on this car. The max never had it when I bought it off some guy.

What about the A/C drain? When you park your car after using the A/C, do you see a puddle form under the car? If the drain is clogged, that condensation will end up on your carpet.

Another possibility. A crack or rusted out hole in the floor pan. This happened on an '84 Mustang I once owned. Running through a puddle in the rain would cause the water to splash up and soak the carpet.

I rarely ever use the A/C. It's not even summer anymore so that's out of the picture. I can check underneath the body for any holes but for a wet spot that big?