I have a 2014 MKZ with a panoramic sunroof. The glass slides back and forth with ease. No issues there. The one that I do have is that the sunshade has become "unglued" to the track and the track is now malfunctioning. The shade will slide back and forth, but rather than roll up neatly when pulled back, it just bunches and droops down. I want to replace it without the costly repair of the entire shade. Is it possible to just have the track repaired?