Ok, here we have the 2012 Impreza 2.0i Sport Limited. I will be doing a OEM LED mirror retrofit. First you need to order the following parts:
4 - Solderless Terminals
4 - OEM Screws Part No. 91039AJ500 $00.71 each
1 - Left Cover Part No. 91059AJ210 $33.71
1 - Right Cover Part No. 91059AJ200 $33.71
1 - Left Lens Part No. 84401AJ010 $67.48
1 - Right Lens Part No. 84401AJ000 $67.48
PLUS + $14.00 shipping comes out to $219.22
As you can see that one for the mirror covers have the cut out in them. In Japan they paint them and have different part numbers for the painted part, In the USA they only come in that unpainted beige color.
The lens look like it has a slight tint to them, and have a defusser in the plastic to make the LED look brighter.
This is the wire that you are going to connect the POSITIVE + side of the Signal Lens to inside the door harness (YES) it's already there. The white wire with a red stripe is the turn signal.
This is the finished product below and I will take another picture with the cover painted and on the mirror.