Thanks Bud for this comment:
"It's been years since car radios that had a decent AM chip. Remember how good the old AM only car radios sounded."
Yes, I remember...in fact, if you have an older vehicle, there is someone who does resoration on those older classic radios! See here: http://www.bobsradio.com/
Bob will go completely through the radio, replacing old capacitors and out-of-tolerance resistors and other parts, plus all the essential things to make it like new again. The newer, later parts have higher ratings and tighter tolerances for better performance. He can even convert an AM radio to AM/FM without altering the appearance of the radio.
Also, there is a gospel station here in Mobile that is still operating AM stereo. Needless to say, I think the industry, in all their "infinite intelligence", tried to sanction the harder-to-use C-QUAM rather than the better Kahn AM stereo system. Bud, Mobile, AL