My 850 has a sun/moon roof and last night while driving around a odd sound started coming from up inside the headliner between the sun roof and the passenger door. It's sort of hard to describe, kind of sounds like a really BIG bubblebee inside a glass jar or maybe the sound a dirt bike would make 100 yards away running over some hills if you were inside a car with the windows rolled up. This went on for a few minutes until we stopped and turned the engine off. Didn't happen again when the car was restarted. The sun roof worked fine all the time this was happening. Tilted up OK and opened and closed fine. Does anyone know what could be causing this? Except, of course, for a really big bee trapped inside my headliner. My wife was in the car also and yes she heard the "bees" too.

do you have a wind deflector for your moonroof?

This is my wifes car so I don't recall if there's a wind deflector. If so, is there a motor for this or is it mechanical like the 740's? The moonroof was closed when the noise started. I thought it was the bike carrier vibrating but it continued when we were stopped. Very strange sound that at first seeemed like it was coming from outside.

That is usally cause by the strip around the top of the windsheild being loose i had the same problem

Thanks for the reply. This was a really odd sound and I omitted that it also continued to happen when we were stopped. Really sounded like it was coming from outside.

If you have automatic temperature controls for the car, the sound might be coming from the temp sensors which are located behind the handholds above the front doors. These sensors have a tiny fans that pull air across the temp probes. If the fan bearings get worn they will buzz.