They (Gentex) all use the same sensors. Some have a clip, some have a mounting tab, some are round and have a couple claws to hold them into a round hole, etc. You can get them at parts stores, and they aren't expensive. I live about 90 miles from the nearest yard, so it generally costs more to drive to/from the yard than it does to just buy the part new. That's an option if you can't find one at a yard.
I used to buy/sell a few of those mirrors in different fashions, and some are worth more than others. Green display mirrors aren't high demand. BUT some of the others ARE, and easily obtained at a junkyard if you know what vehicles to look for.
They come in different display colors, some have temp, others dont, some have bluetooth, some have compass only, some have a camera, some have map lights built in, etc. What I have found, though, is that once you get one you want, finding wiring instructions online isn't easy. Ebay sellers have harnesses with diagrams, and they aren't real expensive-and probably a good option before you hook up the wrong wires to 12v and fry the board like I did on one of them trying to figure out what wires do what.
IIRC some of the Toyota's and Lexus's had desirable orange display colors, temp and comp built into the mirror without a dedicated window for the temp/comp display, map lights as well....and THOSE are harder to find but kinda cool to have. That's the ones that have a "floating" display, where it appears to be behind the mirror glass. I want one for my two foxes but with a green display to match the cluster, and someday soon (when it ain't raining), I'm going to the yard to load up on a list of crap that I plan on reselling, and will keep a couple for my own projects. The bad part about a lot of the GM stuff is that many of them had that stupid OnStar built into them, which is useless for anything, IMO. Out of about 5,000 cars at the local yard, the last time I looked for a mirror, maybe 25 of them had one that were usable. Then a couple hundred GM cars & trucks with OnStar mirrors. BMW's had some nice ones too, as did Mercedes and the other brands of Toyota and Nissan (Lexus and Infinity, respectively).