I've got a 2011 MCS CM with an issue - We got a hard rain in the Houston area today and my car was sitting in it. I got home from work and happened to open my passenger rear door and noticed a puddle of water on the All Season floor matt. I pulled the floormat up and felt the carpet and noticed that the carpet was soaked as well - Looked at the plastic up the sidewall, the pillars, the headliner and no signs of water dripping - it's isolated to that one floorboard area and I'm at a loss as to where it is coming from... Took it to dealer and had them schedule a time for next Tuesday but was hoping that another may have encountered the same issue and what their fix was.

 

I have the same issue with my countryman. Did the dealer find the leak?

 

This same thing happened to my husbands Jetta wAgon a few weeks ago turned out the little drain was clogged with leaves

 

I just dropped it off with the dealer this morning... I took it through a pressure auto wash without any problems, so hopefully it will re-occur for them (fingers crossed) They are also going to look at the right rear seatback - that thing sounds bad when I hit a bump or get on a stretch of bad road - Just likes to rattle...

I will update with their results for any others with the similar issue I experienced.

 

I had this issue on my 2009 Hardtop Justa and it was due to a small leak at the windshield. The water came down through the cabin filter and into the passenger side floormat just as you described.