Last summer I upgraded my stereo and it went great for a year. I realized that the front to speakers started to sound crackly and eventually stopped working. I took the door apart (to take the speakers out) and realized that the doors were leaking a significant amount of water as the cones were filled with water (the speakers are marine certified but still managed to be affected by the water). I put a hose to the passenger window and realized every drop of water I put on the window, went into the door…. The driver side was not as bad, but still leaks. Does anyone know how to solve this problem, or if they have had a similar problem??

 

I had a very similar problem on my Passat, turned out the leak was up top near the roof, about where the upper right corner of the window (when rolled up) was. I was assuming it was down below where the rubber strip contacts the glass, but it wasn't.

I would say the most important thing to do first is find exactly where the water is getting in, and depending on if it is between 2 different materials or just a simple crack/gap find the best filler solution/substance.