From the number of people asking, I thought I'd at least share what I did to make the facelift mirrors work on my V50.
The biggest setback I had was installing C30
mirrors on a V50
. The triangle shaped piece that attaches to the door was a completely different shape, so I had to disassemble the mirror housing to swap it over (breaking a lot of parts on the original V50 mirrors in the process).
I would suggest finding S40/V50 mirrors if you attempt this upgrade, as the triangle door pieces should line up no problem.
Also, the earlier mirrors are only held on with a single bolt, while the newer mirrors (on the 2008+ C30s) are held on with 3 screws. These screw holes did not line up with any of the pre-drilled holes on the V50, but a facelift V50 mirror housing might line up perfectly. If not, it wouldn't be too hard to drill the holes you need.
Again, I am comparing my facelift C30 mirrors with old V50 mirrors,
I can't confirm that this will be the same for all facelift mirrors and pre-facelift cars, but the wiring diagram did say it was for all P1 models and not specifically the C30 or V50.
The following pictures should be pretty self explanatory if your donor mirrors have the same color wires that mine had.
This first picture shows the wiring harness from my stock V50 mirror which had puddle lights.
This second picture shows the wiring harness from the stock C30 mirror which does not have puddle lights (and I did not wire that part up).
This third picture shows the V50 plug but with the C30 mirror wires running to it.
I assume that the black/red wire on the V50 was for the puddle lights. If your new assemblies have puddle lights, then that first row - second column pin hole should be for the puddle light wiring.
Turn signals, motor adjustment, and defrosting are all functioning properly on my mirrors. I will say that the adjustment motors don't seem as fluid as they used to, but they still adjust as needed.