Can anyone provide a schematic for where the drain tube goes after it enters the A-pillar? Does it make a transition back to rubber at any point? It appears it just dumps inside the rocker? That seems like a recipe for rust problems so I have a hard time believing that is correct. This this is the result of testing the drain (rubber tube in the headline is attached and clean):
https://www.youtube.com/watch?v=wcHS...ature=youtu.be

I pulled wheel, fender liner, and the plastic trim under the rocker panel and didn't see an obvious exit point. The water is mostly draining out of the two plastic push clips that hold the trim on near the jack points. You can also see about halfway through that video a drip comes out from where it is now leaking into the car. I have fished a few guages of solid core wiring into the drain tube but they all get stuck when they read an area mid way down the A-pillar.

 

https://www.northamericanmotoring.co...of-drains.html

Here's a link to a how to on drain service and routing

 

So, searching on real OEM it doesn't give you the greatest one, but it's something. #10 is the water outlet hose 51738197504 and #11 is the water outlet hose rear 54107043425. Some info in this NAM thread here with pictures and a description of where it comes from the front of the car. Hope this helps a bit.

 

I realize now I sent the wrong link....after looking at my link it didn't have that schematic attached in the comments.
Nice save!

 

No worries! There was some good descriptive info about the drains and how to clean them in the thread you linked as well.

 

Thanks for the info, I found the drain exits. The passenger side was easy to clean out. The driver side is being more difficult. I am going to drill a 3/4" clearance hole in the lip of the fender that is blocking better access to the drain exit. I hope the engineers that designed these drains just above the electronics were given an award for most German maintenance access.

 

Here is a photo for anyone else who wants to find them quickly. Drivers side:

 

You're welcome. haha well glad you were able to find them and clean them out!

 

One item of note if you still have wet floors after this check the clips that hold the corner trim pieces above the a pillars. If the foam is rotted and or the clip is limp water will leak in

 

This forum was helpful when I took my R53 in to my local indy garage yesterday to fix the soaking floor and seatbelt after every rain. Sure enough, the drain tube had separated from the feed off the roof and was running down the A pillar into the door. It cost $95 to fix. Whew.

 

The plugged drain holes on my R50 didn't just soak my carpets. Water got to my Body Control Module ($500+) and killed it dead.

Making sure these are always clear should be a really high maintenance priority.