OK this was weird. I was driving home from work, entering an intersection, when I hear this 'clang-de-clang-clang' sound. (like that?

)
Anyway, it turns out my passenger side-view mirror glass fell out due to ??
I found replacement glass in the PP catalog, but my question is how to attach it? Is it glued?
Also, is there any reason I can't just get a glass shop to make a small mirror for me? I am thinking there could be significant cost savings this way, $50 vs $??
As always, thanks in advance
-Chris