Found this via google
I have searched all over the place for an adapter that would plug into my cd-changer input. The other end of the cable would be USB and could use either a flash drive, or mp3 player that can be controlled by my steering wheel controls.
I have a 99 Acura TL, with the factory HU. I am looking for anyway I can send a signal to my HU via USB and have my HU and steering controls also control the tracks.
Any help is much appreciated.