I have the Sony CDX-MP40, a wired remote and I want to attach a HK Drive and Play. Do I need a XA-300 little box to do this or can I just hook up the Drive and Play? I figured out I can not just hook up a head phone jack to RCA cable to the unit because it doesn't allow you to do this without that extra little box. Is there a way I can get my Ipod working without having to buy this little $100 unit. Kind of makes me mad that this can't be a simple plug in and go. I tried to find where I can even turn On the AUX through the head unit but I don't think that is possible.