My daily driver is a 1986 El Camino. Automotive electronics have progressed a LOT in the 25 years since my car was made. I have always hated the bulky garage door openers that hang on the sun visor. I went looking for a solution. I found a rear view mirror with built in garage door openers, a compass and thermometer. The biggest thing I love about it is the automatic dimming of mirror. Now when the big pickup or SUV with the super bright headlights pulls up to my bumper the mirror just darkens automatically. It's wonderful.
It is pretty easy to hook up. One wire with constant 12V one with switched 12V the ground and the temp sensor mounted under the front bumper.
I have no affiliation with the manufacturer or this supplier. This is where I ordered mine and it was shipped promptly. I just thought some of you might like a gadget like this. It is virtually identical to the mirror in my wife's Infinity. I don't think Pelican sells anything like this so I felt it would be OK to post this link.
50-GENK51AHomeLinkCompass/TemperatureAuto-DimmingGentex Harness -- MGT Motorsports Online Store