Its raining cats and dogs in southern CT, I don't usually park outside. I wanted to wash off the polen from my car, hence I parked the car outside in the rain for about an hour. When I took the car back to garage, I found the 'C' pillar (Passenger side) wet (see the pics). what is causing this leak? is it sun roof.
(My dealer also changed the rear glass's outer rubber beads about 2 years back). Any suggestions would be appriciated..
Sorry for the low quality photo, I used my iphone..

 

Probably your sunroof drains... a known problem.

 

Just had the same problem.
Had my drains checked n cleaned by the dealer, but then it still leaked.
So this time they changed the sunroof seal, sunroof caskett, and the whole interior changed where it left stained.( basically got me a whole new roof interior.

If your out of warranty, try o change the sunroof seal.
I had the leak on the same spot as you.

 

I fixed my sunroof seal, the leaking didn't go away....

 

I had the same problem happen when rolled through car the wash in my 530i
but it rained pretty hard the other day and no signs of leaks from that same area, hmm...
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I've had that same problem once and I think I just had the rear window little bit open and when I have alot of speed on the highway the water just flew there. So I think you guys dont have to worry about that !

 

I had the same issue when going thru a car wash. Sun roof seal replacement seemed to have fixed it for me.

 

I would go to the trunk and look in the center area under the mat. A lot of damaged black boxes once water hits them. A common problem. Could end up being very expensive. Lucky you caught it.

 

I had same spot, but when I found it it was already dry, and blue color. I guess it was from the wash. It's raining for day in N.VA but same spot it's still dry. But I replaced sunroof seal.

 

Did you drive while it was raining hard?; I never noticed the leak if the car is on the move during hard rain.