Just had the same thing happen to me in my '98 A6. We've had several days of heavy rain and when I went up a seep incline today---a stream of water came pouring in under the dash through the vent onto the passenger side floor. Looked under the hood and under the cover where the battery, etc. are stored, and the whole compartment apparently had filled with water. Of course, it isn't full now because so much of it had POURED INTO MY CAR! Anway, I'm assuming there's a drain in there somewhere that may be blocked. In the process of trying to find it now... Will let you know if I find something. In the meantime, anyone else have this problem? Or better yet, anyone else SOLVE this problem??