Quick update again...
M3 mirrors now fitted and sorted.
Opted to get the mirror covers colour coded in body colour for a more OEM+ look.
Also got the added bonus of having both passenger & driver mirrors autodimming, since my M3 mirrors were obviously from before BMW got tight and only fitted the drivers side with the electrochrome glass!
My car being a 2016 build was sadly only equipped with one auto dimming mirror glass from the factory, but the good news was that the wiring is present in the door, so it was plug and play once the M3 mirrors were on!
Pics...