So Jack and I walked out to the BMW 530i the other day, open the right rear door and then Jack says "whoa Dad, there's water in your car". We had had 3 consecutive days of rain (which is rare in Southern California) and a few inches of it decided to collect in the floor of the car. I thought to myself "how does this happen?" and "this is a nice car". A little research from my wife Kelly discovered that this is a typical problem with the e39. And after a little visual inspection and simple repair on my part, it was obvious that it was a quality control issue at the BMW assembly plant (either the adhesive was poor or the vapor barrier wasn't seated properly - see the pic below).
Learn how I fixed this issue after the jump.
Thanks to a couple of posts from bimmerforums.com and bmwtips.com, I was able to understand what the problem was and how to fix it. I won't go into too many details here and will instead refer to the original posts. But in short, the leakage happens as a result of water coming in through the crack in the door, where the window slides down. Water then is supposed to deflect off the vapor barrier and exit out two drain plugs in the bottom of the door, then to the outside of the car.
Problems arise when the vapor barrier becomes detached from the door and water then leaks from behind the door panel, down the rocker panel and into the floor of the car. To repair the vapor barrier, but the basic steps are:
This post is not that instructional. Refer to the links for more details.