Just for any of you out there installing this mirror and only have the harness that comes with the mirror, it is a 6 pin connector and you need to use pin #'s 6,4, and 3, #6 is a yellow wire and would be for the reverse light input, # 4 is a violet wire and is used to connect to switched 12 volts, and the # 3 is a black wire and is used for ground. The #'s are inside where the pins come out and are numbered 6.5.4.3.2. and 1 (when looking at the inside of the connector) hope this helps some one in the future. Although I have not done anything for the reverse light, I'm just going to live with it working all the time.

I will say this, this option should of came with all the Xfires it is really a neat addition
And thanks to OCR-XFR for the great write up