I have to have AM and MP3 on a head unit and have never had an after market head unit get any AM stations so I want to hook up an extra head unit and from that head unit have 2 amps for subs and speakers. I know this sounds stupid but I can not find a head unit that will play MP3 and pick-up AM stations so I am going to keep the stock HU for the AM with the factory speakers and then have the other head unit a MP3 head unit and have that wired to subs and separate speakers from the stock head unit. Is this possible? How do you do this? Is there another way to get AM stations to escape this nightmare? Thanks Brad