Originally Posted by bmrboi2

Could be but doubtful. 99.9% of my BMW water leaks have been because of a sunroof leak or a roof antenna leak. Have you ever waxed the vehicle? Every time I do which is almost every 1-3 months using a heavy, generous coat of carnuba wax (mothers) I give all of the rubber gaskets including the windscreen and sunroof a good once over. This keeps my seals soft and pliable. I had this problem with the seals cracking on my E36 and E46. But not on my newer ones. I am assuming this is around the back door windows? Sorry if that is or isnt helpful.