Volkswagen 1998 and later automobiles are equipped with a trunk mounted CD Changer interface. This is great for hooking up an auxiliary audio device to your car’s sound system because it is pre-wired for you. However, Volkswagen’s OEM head units lock this interface from being used by anything but a Volkswagen CD Changer by muting the audio inputs unless there is a valid data stream coming from the CD Changer. The VWCDPIC Audio Interface Adapter is a « lock pick, » if you will, that unlocks the CD Changer interface by sending the required data stream, fooling the head unit into thinking a CD Changer is connected.