I took a look at the existing setup in my 156. I can't for the life of me work out how the old one, or it housing comes away from the glass! I have managed to undo a plastic flap near behind the mirror. That's it. I don't want to go prying at anything as it all feels very solidly fixed. From the roof I have a plastic trim piece that refuses to be removed, then a large plastic trim piece which incorporates the rain sensor arm thing, and a plastic arm bit that the mirror screws on to. Then lower down there's a plastic flap that I can open, on the inside of the flap is a metal spring with a plate in the end that pushes against something attached to the screen when the flap is shut. I have got the dipping mirror on by unscrewing the original mirror from the arm, and screwing on the new one. I'd like to get the trims off to route the cables out of sight. I can't get the old bit of tape cover coat hanger down from the interior light hole.
Any ideas on removing the trim, which bits to remove or what that flap with a spring behind could do?
Interestingly, there is a slot vast in the flap which would be the perfect size for the wiring for the mirror to go through invisibly!