<P> A factory headrest on a Pontiac Fiero embedded with stereo speakers . Eliminated on later models due to cost . </P> <Li> <P> A set of speaker drivers removed from a passenger vehicle </P> </Li> <P> A set of speaker drivers removed from a passenger vehicle </P> <Li> <P> A car audio amplifier </P> </Li>

When did they start making aux cords in cars