Wet floors (front and back seats) - Toyota Highlander 2002

This is normally caused by blocked sunroof drains. Do you have one?

https://www.google.com/search?q=2013+nissan+quest+blocked+sunroof+drain

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take a wet and dry vac and push it all around under the dash do not break anything , turn it on and go to town where you think they are , try it this way you do not have to tear everything apart, let me know how this works out for ya ,

Have you checked the rubber door seals for ingress?

your ac drain is blocked

should maybe be cabin filters look for trap door in back side of glove compartment..replace if necessary not sure if car is equipt most are...

Sounds like it's time to replace your cabin air filter. These tend to smell over time especially in vehicles where the owner smokes.

check the seal on your windshield most leaks sometimes start from windshield

Look under the passenger side of the dash, behind the carpet. Feel the back side of the carpet for dampness. If so, try this: In the same area, look for a black rubber hose that comes from the heater plastic box, and pokes thru the firewall. See if it is plugged up. This is the drain pipe for the AC box, and the cowl panel if the side drains are plugged up. Try that, and please get back to me.

run water over the winshield ..keep eye on the fire wall and sides. also check the florr if is wet. water is likin somewere

Wow I thought they would have fixed this on the newer body style. My old 2000 A6 had the same issue. There is a drain in front of the bulkhead that gets blocked, in my case by pine needles from my tree. I used a coat hanger to clear it and then cleaned it every couple of months and no more drowning carpet. It used to be next to the battery(which they moved to the trunk) under the windshield wiper motor. I haven't checked the exact location on my 2005 but good to know it's still an issue.