It's a window alright , but it's made of sheet metal and you need an x-ray to see through it.

At least you didn't get the "could not replicate" stamp that seems to pervade all in-warranty problems. Plus you should consider yourself lucky, last time my car was road tested for a problem, the odometer read 1 mile more than when I dropped it off.

In all seriousness, wow, 24,000 miles and this frequent of a problem! Keep us updated as to what BMW will say. BTW, which version of "the lurch" would you classify as your ailment?