"Car" radios were more about "sound" than quality of such, back then. AM radios had their static issues plus a limited frequency response range that was possible for that format. In the middle 1980s, when "AM Stereo" tried to get off the ground (GM had that option on some of their higher-level factory radios, and it DID sound almost as good as the normal FM Stereo stations, back then). FM's advantage was that it was not affected by electrical interference from many sources, inside and outside of the car.
The 8-track tapes' advantage was that it took the "quietness" of FM and made the music portable and customizable. The tape speed of about 3.75 inches/second (1/2 of what a home reel-to-reel tape recorder/player used) was plenty good for sound frequencies of about 100hz-10Khz, with some better quality tapes going up from there, for those that cared. Cassettes ran at 1/2 the 8-track tape speed, which made the tape quality much more important for good 8Khz+ frequencies, with higher-density magnetic media and such. Plus the ability to easily record at will, on the portable units and the '72 Chrysler optional players.
There were some 8-track recorders back then, for the home market, but they were more about transferring music than pure recording one's own music, as I recall, back then. A device that was sitting on a table or desk, non-portable, as a general rule.
As good as the Chrysler car units were, the ultimate best radios were still the "home units". With 100W amps, speakers that would hit the full audible frequency range, and speakers that could be placed to accentuate the "right channel/left channel" orientation for a very good stereo experience, rather than just "sound" (i.e., "boombox" sound with no channel separation).
In the earlier years of stereo vinyl, it seemed that the sound engineers seemed to work to accentuate the "stereo experience" of side-to-side separation. With the overlapping signals filling in the gap between the speakers, so to speak. Sounded really neat, especially on orchestral music where you could pick out where the various instruments were seated in the orchestra, side to side, for a really good sound experience . . . if you cared about such.
So, Chrysler's 5-speaker factory stereo radios provided probably the best sound experience of any OEM back then, from what I heard myself. Some people appreciated it, given its automotive environment, as others probably did not. BTAIM. Doing it all with the available amplifier power of back then with available speaker technologies, too. A good pre-cursor to what was to come later with the Alpine-built "spatial imaging" sound systems in the LH Chryslers.
To me, one of the things that really made the factory stereos work was the placement of the front speakers aimed upward, so their sound reflected off of the windshield, rather than being "buried" under the instrument panel in the kick panels. Such that the sound could be imaged from the windshield, for a nice "front row concert experience" (concerts, back then, were typically orchestral in nature rather than otherwise). With their better amps and speakers, even the later Chrysler Formals had very good 4-speaker systems. With enough distance between all of the speakers to kind of give that "concert hall" experience.
Enjoy!
CBODY67