Selling a Grom Audio USB/iPod/AUX Interface Adapter. It will work with any E46 that is pre-wired for a 6CD changer. This unit connects through those wires and allows you to select between each of the 3 media. Straight up, the USB interface is garbage. You're pretty much buying this for the AUX and iPod capability. I switched to OEM BMW AUX input kit which is why I don't need this anymore. $100 obo.