Is the wiring already in the mirror housing, Making this an easy plug in? I've Been wanting to do this to mine but wasn't going to spend $300+! This would be great. (cabpatch)
The wiring is not present in the mirror housing. If you click on the walkthrough linked about you'll get an idea of what you need to do for this install.
UPDATE: I did the install today on my father's '08 Mz5 touring, and there were several differences between the 3 and the 5. I'll go through those and let you know what I did.
1) The harness plug to the mirror is opposite that of the 3. Meaning the pins are on the car side, and the receivers are on the mirror side. It's super easy to add the pins on the 3, however adding receivers isn't really in the cards without the specific part from the plug, and Mazda doesn't sell those individually. To get around this I literally "got around it"..... I just bypassed the white plug completely, ran the wire out next to the plug and used wire taps to connect to the heater wires on the car side of the plug. The wires you need to use are a black one and a green one..... there are actually two green ones, but it will be the green one next to the black one. If you look inside the plug where the pins are there will be three pins on one side, and two on the other. You want to use the wires associated with the two pins as the three together are for the power mirrors. Since there isn't a lot of room to work with on those wires I pulled the door panel off the inside of the door to give myself more room to work. Plus doing that hid the wire taps on the inside of the panel.
2) The wire routing by the white plug is a little different than the 3, but it's pretty obvious once you're looking at it.
3) If you're doing this in a cold environment let the mirrors/housings warm up for a while inside before trying to remove the glass...... I didn't on the first one and ended up cracking the stock glass. No problems on the other one since it was warm by the time I got to it.
All in all I'm happy with the end results, though of course wish it had come out as "clean" as the install on my 3. If anyone's wanting to add these to their car I recommend it.... honestly I needed the two pieces of glass (~$50), +/- 2' of wire (already had some), four mini female spade connectors (had some), and four wire taps (also had some). If you don't have the additional stuff then it can easily be had for <$10.