To anyone needing help finding a Gentex mirror, I would advise you to just visit your local U Pull lot for the best prices. I just pulled 3 more to wire up in the family fleet of vehicles (cheaper than buying a universal clicker for each vehicle!). The most common will be Auto Dimming + Homelink (all that I really need). You can find them with the compass and or temperature add-on if you're lucky.
You want post 2000's vehicles. The newer, the better.
Next, Gentex mirrors are used in a lot of vehicles as upper or premium options. Base model something? Pass. Look at a vehicle/trim that you know is decked out. GM trims have mirrors with their proprietary OnStar button. I pass on these also.
You'll need a small star bit to loosen the base of the mirror (keep the screw!), the pig tail (cut off as much as you can, fish it out of the headliner), the plastic piece that'll cover the exposed wire harness (careful, its fragile), and the mirror itself.
**If you're pulling a mirror with the TEMP function, you'll need the temperature dongle. It's usually mounted in front of the radiator/crash beam. I have yet to find one in my yard as the crash beam is ripped out when the wreckers pull the engine and transmission.**
So far, I've pulled Gentex mirrors off 2x Prius, Nissan Maxima, and an Infinity M35. Paid $10.00 a piece. Once you know which vehicles to hunt for / which to avoid, you can find them pretty easily.
Happy hunting and modding!