Water Leak from headliner roof into cabin

[balx5]

Alright I think I ran into another maintenance work here. Took the X through the car wash with wife and kids in the vehicle. Water started to drip on my wife from the rear right headliner courtesy light area. As you can imagine it was quite shocking to know your vehicle is leaking water from a simple no touch car wash. I assume there is a clog in the drain somewhere so I searched the forums and only came up with this but no solution.

http://www.xoutpost.com/bmw-sav-foru...f-diy-e70.html

Anyone have experience this and have a solution or DIY. I can post another DIY but just needs some of the folks that has experience this before for their take. Thanks.