I haven't done it yet.. but I'm planning to do it in the future. I got an overhead console and autolamp / autotint mirror sitting here, I just don't have the time to get it all installed right now (pulling down headliner etc..)
Once you have it physically in place, it's not that hard to set up if you can do some wiring, basically the mirror has to be hooked to switched power, constant power, and then it has an +12v trigger for a relay that turns the lights on. If you are ripping out the stuff at the junkyard, look for the autolamp relays, or else you can just use some regular automotive relays. It takes two relays, one on the park light circuit and one on the headlamp circuit.
Also the mirror I have seems to have the GM style mounting base, which means some creativity in removing the factory mount on the windshield will be needed and then the new one will need to be glued on.