Yeah, I think that the sprey glue is a good idea. I usually just use the 3M stuff. My car is having the same problem. The only issue is that the sunroof has it too, so I am gona have to deal with that too, which I hear is a real pain.
Rubber Cement, the kind that has the little brush attached to the lid; works great for areas that you can't spray. My sunroof panel had the liner lifting up around the edges. Brush a small amount ofcement on the liner and the panel, wait a minute or two for it to tack up, push the liner to the panel and use clothes pins to hold it together as it dries.