Not posted on a forum before, but had to contribute and hopefully add some clarity to the regular issue I read about e88 roof motor failure and water ingress. I’ve got a 2008 e88 120i, same issue as most with water logged motor, PDC damage etc, but found no issue with leaking back lights etc suggested by others.
Well I found the usual collection of water under the roof in the storage area (you can see the drainage channel if you get the roof half open and the rear lid up) but then went on a hunt on Google to try and find out where the channel exits, but found nothing. After much head-scratching I removed the rear wheel arch liner and bingo, there it was, half-way up, the clogged rubber boot. It seems the channel blocks, water collects in the storage area above and then on acceleration, a tide of water washes into the boat space where the motor sits. I hope this helps someone else as I had no idea where the drain exit was. I also replaced the motor for £40, well happy!!
