The first in-car cassette tape players emerged in the 1970s ... along with that terrifying feeling of a unit “eating” one of your precious tapes. The last OEM cassette decks didn’t disappear until 2010.
The 1970s also ushered in what we now refer to as “aftermarket” sound systems for drivers who wanted better quality than what was available from the dealer. By the 1980s, removable receivers were introduced so that car owners could protect their sound systems from auto break-ins.
Also in the 1980s, car stereos became available that rivaled the sound quality of the best in-home systems — including units with multiple speaker configurations.