Seems like the AM/8Track radios were listed as "dual audio" radios. These were the in-dash combination factory production units, which also might have been listed in the Accessory section of the Chrysler parts books for dealer installation/upgrade. Seems like Mopar also initially had some accessory 8 Track under dash units too, which were possibly repackaged "to Mopar specs" units from an existing manufacturer of the time. The base speakers for the AM/8Track would have been two speakers in the front with rear speakers on the larger and more expensive cars in the mix too. A different setup than what the later 5 speaker factory setups used (which had the divider box).