We had another that the cover was loose. He tightened it by using a plastic ziplock freezer bag and put it on the ball for the mirror and then applied the mirror. It snuged enough to keep it in place. A real shame if you glue it!

 

That is a good idea Gus. Just make the compression better instead of glueing. I have not removed my broken mirror as of yet as I am still looking for cheaper than $40..but might just have to bite it and pay for that.