WaxLyrical
Honorary Master
I wouldn't do that if I were you. For the Caddy bus at work somebody replaced the glass with one that was cut, doesn't look the same at all. All car mirrors are expensive nowadays, you should replace with an original if you can.
Yes because vehicle mirrors are plastic based whereas the mirror specialists do glass.
Also the mirrors themselves have a hardened plastic border which gives it the distinctive vehicle mirror look.
The cheapest option would be to make a template, get a makeup mirror from the China Mall, cut it a with a blade and stick it over the existing cracked mirror.
Not pretty but you'll be saving a pretty penny until​ you decide to sell.