general problems of the 2001 Volvo S40

Something, possibly a rail, flew off of my Volvo S40 (2001) on the highway. Subsequently, the sunroof was unable to close because of getting hung up on the sunshade. When I brought it into the shop, I learned that the rails which had held the sunroof in place had become detached from the glass because the glue applied in the factory to attach the metal rails to the glass was no longer even visible. I do not believe the rail hit another car when it flew off the car, but this incident could have had very serious consequences.