This is strange.
We have a 2001 Deville. It has the passenger side mirror that lowers when you back up (to show the curb) then straightens when you go into drive. The other day my wife was backing out of the driveway. The mirror lowered but, when she put the car in drive, the mirror exploded from its housing and bounced off the passenger side window with a loud impact. The mirror was smashed and hanging by its wiring. We have a warranty on the car. The dealer says he doesn't know if GM will cover the repair, which will possibly be $700, as the mirror looks a though somebody physically smashed it. He never heard of such a thing as the mirror flying out. Does anybody out there know of any similar incidents?