Usually when the regulator goes bad, or it gets cracked, the windows binds as it moves up and down and puts pressure on the mounting points... I've seen several regulators cracked into several pieces from this, but never broken mounting points on the door itself. O_O.

I would say pull the regulator out and take a good look at it.

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Current cars:
2000 ML55 AMG, 174k miles
2003 C240 T-Modell, 202k miles
1995 S320, 207k Miles