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Arent hardtop BMW's suppose to be water resistant?

My BMW wagon is a 2006 model and I’ve been super frustrated that my roof leaks in moderate to heavy rain through the moonroof. This has occurred 3xs and was twice covered by BMW. But now it seems it’s my fault with the dealer claiming the channels were clogged. The drain system for this car is suppose to leak through the double-panel moonroof and then follow rubber tubing channels through the car to vent under the car (when it works). I’ve traded stories with other owners of same make and model and many have same issue. Trying to find a permanent solution so I can feel confident again to leave the car out in the rain. A guy in UK claims he found a garage that fixed problem by completely replacing the rubber tubing with a hard plastic tubing. BMW of course wont admit to this fix nor suggest it as it would show the product design is wrong from start. I’m trying to confirm if this is best route for me. Thanks for any feedback.

That is a universal issue.  It is not limited to BMW.  

 It is possible you may be parking somewhere that is subject to some sort of material in the air and that may be the source of repeated issues.  Do you park under or close to a tree somewhere or in a dusty area?

To break down your post, correct me if I paraphrase wrong. Water is entering the inside of the car at some point around the moonroof to body seal(indicating that this water is not able to take the drain path provided). This problem has occured before and a cleaning of the drain channels fixed the problem. The problem has returned and a cleaning of these same channels does not eleminate the leak as it has previously done.

OR, cleaning of the drain channels does work as it previously has but you do not think you should have to keep cleaning out these channels so often.Do I have this correct?

The dealer couldnt prove any clog when I asked to see it. The only tree near where I park is a Magnolia and it doesnt issue debris that small. Further, I seldom keep the roof open to collect enough and it is at road speed so how could it collect especially when the roof is closed when parked?

Water pools at the lowest point where the spare tire and the entire electrical system is located. So the damage that occurs most is from a fryed electrical system. The first time dealer instituted a replacement of the entire moonroof system which a dealer is suppose to follow. They did at no cost. Included new seals, channels to drains. Subsequent fixes were to “clean” the channels in moon roof and pull of the tubing to “clean” residue build up" that was supposedly causing water to find its way to the spare tire area.

I’ve now seen the rubber tubing channels myself and they are made of very soft material with a small diameter so the chances of clogging are greater. I’m asking how other owners have resolved this issue and if the UK owner fix as I describe is common enough to suggest a path forward.


I see a path for you in presenting a case to BMW that a repair done under warranty only got the car out of warranty but never eliminated the continuing nature of the problem. Perhaps you present the situation to BMW that you will be satisfied with them continuing to “service” this condition for a set time period.

You are really asking if the "fix’ come up with by other BMW owners is worth doing and I must reply that if the fix does what you claim and BMW is of no help you have little other choice than doing it, as you say it is endangering the electrical system. Simply ignoring the problem since the car is out of warranty is not an option I would accept.