I have YET to find out what CD/AUX does other than operate the CD player. To access XM, it's done via the AM/FM (Band) button.

I'm sure we'll chat before Carlisle.

 

It should operate more. Auxiliary refers to any add ons. I think this was for a multi-disk CD changer. So you can use that same 5 pin 3.5mm jack to 'capture' the CD. You'll just need a cd in. Some people report hearing the CD still playing if the radio is turned to a high volume and the devices 'hacked' in is playing nothing. Some people have burned a black track for the CD.