I recently purchased an '05 TL w/NAV and 6-MT. Today I realized there is a cut cable behind the stereo unit. I have not traced it to see what the connector looks like, but the cable itself is about 1/4" diameter, and contains several wires in it. All the normal functionality appears to be working (Nav, CD, radio, XM, etc). Is there an auxiliary input into the stereo this cable could have been used for? Any other thoughts?

Thanks,
Kevin