This may not be exactly the right product but with a bit of hunting you may find something similar that suits the bill, cut a slot in the top to mount the mirror in and stick or bond the rest to the inside, that way you can stick the seal in first then mount the mirror after (or replace if the mirror breaks)

Great idea; I'll give it a bash. Thanks

id do it the same way as you done with the glue but tape off a neat line and use black sikaflex. smooth it over with your finger thenremove the tape.

Hi guys. I was wondering if anyone could help me out: I've made a carbon-fibre wing mirror from a mould I made from the original part (off my Kawasaki Ninja ZX6R 636 2014), though the original wing mirror had a ledge within it so that the manufacturer could just "clip" the mirror glass into the wing itself without need for glues or backing plates. I tried using hot glue from my glue gun to hold the mirror in place, though it looks pretty rubbish having glue visible on the circumference of the mirror glass.