Thank you all so much for the suggestions, and simoncpw for the link. I tried my best searching for that thread, as I had seen that before, but a search on 'leak' or 'leaking' or 'pano' or ... on the title of the threads did not result in it. That now makes sense, since the title is 'water in my...'
I certainly hope this is the case, and thinking about it now, if the drains are plugged at the bottom (as Weasel suggests in that thread), then kinda makes sense... since this has happened only under heavy rain conditions with car parked for over a few hours outside. I assume a slight leak would drain down and start to fill up the drain hose and finally when it is full, it starts to show up in the cabin through the over head console.
I will try and get to it, and if I can, I will take many pictures and post up.
killcrap, thanks for the info on the warped cassette and BMW's foam fix. That would be my next step if it proves to be more than just a clogged passage.
I will keep you posted on the progress. If anyone else has any suggestions or things to add to this thread meanwhile, don't be shy.
