I looked up the XA-C40 and I don't know why I even need that since I don't plan to add an Ipod or CD changer. It seems the purpose is to run up to 3 different accessories such as CD changers, MP3, and Sat Radio.
If I just want Sat Radio, do I need the XA-C40?
I don't know if it has something to do with the remotes and numbers of input. I didn't ask for it, the dealer said I needed it.