One problem related to sun roof has been reported for the 1997 Volkswagen Passat. The most recently reported issues are listed below.
Sunroof suddenly and loudly exploded outwards from cabin after about 10 minutes of driving with heat on high/medium high at approx 65 mph. Sliding sunroof partition was open. Only a few pieces of glass fell into cabin, but entire sunroof was shattered into thousands of uniform pieces, expanding outward from cabin and remaining in a slightly outwards expanded shape.