Hey djh144
Thanks for the tip using the trimmer cord. That sounds like it will work well.

 

(Passenger side)
I removed the side panel to reach back and disconnect the rubber grommet.
I then removed the A Pillar cover (its only one screw behind the airbag logo plug), cut the two pieces of tape, and pulled the tube up through the dash. I could not get enough leverage through the side panel to work the trimmer line through (it was REALLY clogged).

There seemed to be 3 places where mine was really clogged-
1. at the crosspoint in the grommet. (fixed last fall)
2. at the bottom of the A pillar where the black tube meets the clear tube
3. somewhere near the top corner where i believe another tube fitting comes together.

To me, the multiple clogs reasoned for the leaking in both headliner and floorboard.

I also have a theory that during extremely hard rains, the trough beneath the sunroof actually fills up completely and spills over into the headliner causing leaks through the mic.

There is a youtube video where I guy explains the process of threading a rag through with string to help clean it out. I was a little hesitant to try this since tying the trimmer wire is not very tight. I was afraid the rag would come lose in the pipes and clog itself. My solution was to use toilet tissue (im an engineer, just not a mechanical one). It in fact did come lose, but I was able to break it up with a little water and pull it through by knotting the trimmer wire. The clear pipe, is now COMPLETELY clear.

I then turned to the old locker room friend, Gold Bond. I sprinkled the powder under the carpet to kill any mildew or mold that may try to grow. It also speeds up the drying process. Don't overdue it though as it could cause your wiring to dry out and crack.

As I mentioned, I am an engineer- electrical to be specific. I'll be at SXSW this week, but next week I'm going to take the vehicle schematic and probe the lines with an SMU to verify there was no electrical damage done by the rain. I'm also planning on adding a safety capacitive circuit for safe grounding in case the leak comes back. From what I can tell, one does not exist right now. If there's enough interest, I'll write up a guide for testing yourselves.