Getting ready to mount my mirror that I purchased off Ebay. It has a pretty shiny "skin" on the base still. I assume glue of some sort. Could even be crazy glue. Should I be removing glue down to metal(?) to attach my new pad I bought from 914rubber? Razor blade, sand paper, or leave it and go for it?
Click to view attachment

Clean it off with a razor

Clean it off really good and get the factory mirror adhesive pad. It’s a 3m double sided tape and easy to install.

George from AutoAtlanta recommended this in a recent post of mine and it was the easiest rearview mirror install I’ve ever done.