I noticed my floor mat was wet on the backside when I pulled it out to vacume, the carpet is damp right in the center of the drivers floor board. I'm trying to figure out why its damp. It hasn't rained in three weeks, but I let the the hose around the windshield and door and thier is no water coming in, and the carpet is dry along the firewall and door edge so it doesn't appear to be a leak. Can heat from the exhuast cause condensation? The spot is right over the exhaust pipe and I did do an eight hour road trip yesturday.