Typically refers to input sockets that go to the head unit in a vehicle. The analog AUX jack enables any ... and other digital players. See audio jack and USB. THIS DEFINITION IS FOR PERSONAL ...

Why auxiliary audio inputs haven’t been standard ... you’ll need to buy an entire upgrade package just to get an audio jack on the dash. [Jon W’s] Hyundai Sonata didn’t have that bells ...

He altered the head unit to play MP3 files from USB ... auxiliary line-in. But looking at it you’d never know. That’s thanks to the work he did to create a false button hiding the audio jack ...