I want to make an 1/8 in aux input for the factory radio. My idea is to tap into the CD changer input to plug in my laptop and play my music. Only problem is, how to fool the radio into thinking a CD changer is installed. I took the radio apart, all the connections are labeled and most are obvious. The 20 pin plug is the only one used on my LX. It uses all but pins 3,4,11,12,13 and 14. The 14 pin plug is not used (I don't have a changer). The radio is capable of controlling one. I'm pretty sure the audio inputs for the changer are CHG L, CHG R and CHG S.G. The BATT, GND, ACC and ILUM all act the same as the 20 pin plug. What I don't know is what are SHI G, BUS SHI, BUS G, NC and BUS? When a changer is installed does it just close a circuit or is it sending a signal to tell the radio it's there?