I have a 2001 Cadillac Catera Sport. I was looking into getting a single 12 inch sub to put in my trunk to add a little bump to the already stock bose system. I didn't want to change my whole headunit though because it has a tape and cd and I like to use the tape to play my ipod through it. Also I don't feel like paying for another headunit anyway so is there anyone I can hook up the sub to my stock headunit?