Well, I truly feel like a bona-fide member of the X5 fraternity now! I finally experienced my first problem with the X5.
Two days ago, my passenger side window got stuck fully rolled down. For a little while now, it had been operating with a clunk - which I should have known better than to ignore it.
I have done a search of the site and found a lot of very useful information about removing the door panel, replacing the regulator, and most valuable - replacing the window clips. I can only hope that my case is just the clips and not the regulator.
The motor works and the window comes up just a smidgen when you operate the switch. I will record what I find and also the end result / solution.
I guess it had something had to come up eventually......