Just recently whilst attempting to tilt the sunroof, I heard a nice bang and noticed that one side of the roof didnt tilt. I closed the roof then tried fully opening it, which worked fine. Now it won't park properly as one side fails to push the rear of the roof in to position. I have removed the glass panel and noticed that the mechanism for lifting the roof has no solidity to it. I can slide the bracket up and down with no resistance, however, on the other side it is totaly solid and moves only when the button is pressed. I suspect that the guide has broken. Has anyone changed one of these or know just how involved it is?