The arms for the sunroof wind deflector may break; if the broken pieces are not removed, they can jam the sunroof.Google+
Car Problem Reports
Mercedes-Benz ML320 Arms for Sunroof Wind Deflector May Break
Mercedes-Benz ML320 Problem
Average Mileage: 100,833 mi (55,000 mi - 160,000 mi)
Visitor, 1999 Mercedes-Benz ML320, 55,000 mi
Plastic piece which anchors the metal control arm of the sunroof deflector broke causing metal arm to bend as sunroof was closing. I removed the bent arm and held down the deflector by hand to get the sunroof closed. Replacement parts would have been over $200 but dealer offered to remove the deflector for free. The sunroof works almost as well without the deflector.
Visitor, 2002 Mercedes-Benz ML320, 70,000 mi
The Arm for Sunroof Wind Deflector just broke
Visitor, 2001 Mercedes-Benz ML320
Fell on my head while driving and scared me out of my mind, did not know what hit me!