1998 Volkswagen Passat wipers, windshield & visibility problems

This is the second time sunroof mechanisms fractured. This time they struck the driver while driving (pulling out of the driveway). In both failures, there were fractures of the mechanism. The second occurrence resulted in pieces flying off the car and striking the driver in the right shoulder.

Sunroof spontaneously opens and closes without warning. When it opens, it is impossible to get it closed with the switch as it never returns to a predictable position based on the markings on the switch. Once open, it may close itself at randomly and unpredictably. When it is open, I'm afraid to get my hand near it for fear it will close and pinch me. It has also spontaneously opened during rainstorms which causes me to divert my attention to the road attempting to close it.