I know this has been asked and answered but my issue seems a little different and I have tried everything.
when it rains the reservoirs under the carpet in the front and back passenger side accumulate a lot of water. Seems mostly in the back the majority of water is, but I don’t know if it just runs back there? The thing is my top carpet stays dry. The car will not be driven just sitting outside and it rains and the back reservoir will have an inch of standing water under the carpet and front will be wet but not the same accumulation. I have re routed the sunroof drains down through the AC line so that is not the issue. Luckily the water is not up by the electrical stuff my passenger feet it is just under carpet. I don’t see really anything that indicates it’s coming through the door and my first question is if there was a fault somewhere in my door seal would that much water accumulate in that area when the car is just parked?
I have really checked everything I can find to check on this. Doesn’t appear to be cabin air fitting. And it’s definitely not coolant.
so please, I have been fighting this for weeks and I live in Portland so I can’t even drive the car and it’s completely taken apart at this time.
should I just do door seals as next step? It’s 200 so if you think that wouldn’t be the issue please let me know, I’d rather not spend that much if that wouldn’t cause this issue.
again thanks for looking.

 

I can't speak for why it would accumulate in the back (rear sunroof drains maybe?) I too have been chasing a leak for weeks but in the front, which ended up being due to two things: 1) Driver side firewall grommet not sitting flush, thus letting water down the interior firewall and accumulating, and 2) both driver and passenger side A-pillars had debris built up essentially damming up the drain channel, and also both pillars had broken clips in them. I ended up running some marine weather stripping all the way across the A-pillars behind the plastic pieces (just above the pillar clips), and cleaned up the drain channels.

Hope you can find a remedy, I know how frustrating it is!

BTW, I also replaced both upper door seals and both of the a-shaped seals above the tweeter area. If you do end up replacing them, I recommend trying to order from Japan.

Good luck!

 

thank you for the Information. Would the drivers side grommet cause flooding in the passenger reservoirs?
My next step is new weatherstripping, I was ordered from Z1 and it was just expensive so wasn’t looking forward to it. I have taken off the A Pillars and checked for debris and rerouted the sunroof drains into the AC drain. Or next I was going to let it dry and while it’s taken apart go to car wash and just see where it’s coming from.

 

No I wouldn't think so, but there is also one on the passenger side, somewhere behind the battery I believe. There are posts scattered around on here discussing that potential for a leak as well. It could also be a leak due to the seal within the cowl. I believe that causes the cabin air filter area to be wet along with water getting into the passenger floor area....something to consider and check.