Welcome to the site.
They changed them after the poor design in the 14's.
There is a "track" on the edge of the bellow, you have to slide it along the edge of the sunroof glass, and if memory serves right, they will never stay in place, unless you "adhere" them back in place.
I would honestly see if you can order a new set from a 16 up, much better fit, they hide all of the inner workings of the sunroof tracks and stay in place.
The ones you are dealing with are almost and after thought for a design.