I’m guessing that among this crowd, many have vehicles old enough that they have needed to replace the head unit. I am also guessing that most of us are looking for good AM/FM reception and a clear display that is readable day or night. Most head units these days use tiny thin font to cram the display with information about the status of features that I don’t care about. They also cover the faceplate with buttons too small for me to press, marked with microscopic words and symbols.
My internet searches indicate that Pioneer used to have the best radio reception, but that was 15 years ago when people cared about radio reception…
My '97 BMW has an in-glass antenna with an antenna amplifier, so a radio that plays nice with an amplifier and has a switched power output for the ‘electric antenna’ (for the amplifier) would be handy.
CD would be nice but not critical. Bluetooth not needed as it just runs down phone batteries and most aftermarket car radio bluetooth phone connections are terrible.
USB and Aux inputs are requirements but every head unit has those these days. It is old style single DIN height, of course.
Getting to picky details, on this car, output goes to a Harmon-Kardon Amp that splits out frequencies among 12 speakers. The amp expects speaker level inputs, but I dare not feed it too many watts for fear of blowing it up. I have not been able to determine the wattage of the original head unit or the impedance the amp shows the head unit. I know that when the original amp failed, I bypassed it and was able to temporarily use four speakers driven directly by the original head unit with no problem. I think that the European style amp expects the sound to arrive on two hot wires of reversed polarity rather than one hot wire and one chassis ground wire. I don’t think that matters going this direction but I would not have been able to send the output of the original head unit to an aftermarket amp because it would have assumed that half the sound wires were common with each other and ground.
P.S. I asked this question of the Crutchfield customer support email and they did not respond.
Suggestions that meet any of these criteria are appreciated.