I retro-fitted a B6 Auto-Dipping Mirror - purchased the mirror from the stealers ~£115 inc VAT (2 years ago). Made up my own wiring loom and plug - now know I could have got the plug too with a little bit more research. All works fine including the reverse signal which was the hardest signal to source!
I was going to purchase the "revised" mirror with the on/off switch which also has capability to feed the light sensor signal to your Power Control module to enable the "Auto lights" and "Coming Home lights" - but I decided against this as would have to purchase a new Power Control Module, Light Switch, Additional coming home switch, etc. and alot more changes to the wiring.
The mirror wiring is straight forward however the one signal I had trouble finding was the reverse signal. On a manual this can be picked up in the n/s passenger footwell a-pillar connectiion rack BUT with an Auto (Tiptronic) I eventually found it in the Plenum chamber under the ECU and Transmission CU. Tapped in a feed here.
Auto Dipping Wing mirrors would be nice to add but the glass is around £160 per side! The signals are there on the internal Auto Mirror to feed to the doors. Not sure if there is a cheaper source for this external glass?
Kufatec do a wiring harness for the B6 mirror
B6 Link Here and the B7 mirror
B7 Link Here - they are the same part numbers!
B6 Mirror Wires (no switch on mirror, no light sensor feed for additional features):
Pin 1 = White = +12v (from Fuse S231)
Pin 2 = Black = 0v
Pin 3 = Grey = Reverse Signal (Mirror goes clear if you engage reverse)
Pin 4 = Yellow = Wing Mirror Signal 1
Pin 5 = Brown = Wing Mirror Signal 2
Pin 6 = Interior Light (W1) will require addition of diode (Mirror goes clear if the interior light goes on - did not do this mod!)
On the later B6 mirror, with switch, and light sensor for other features,
Pin 1 = +12v from power control unit
Pin 3 = goes to power control unit (This is used for light sensor output)