I have an 03 Dakota with the factory six disk changer. Does the factory unit have an auxiliary input? I had XM radio in the past but got rid of it because of FM station interference from time to time. I want to get another unit (Sirius this time) but I want a direct connect so I don't have to worry about the FM stations. Is there an auxiliary or another option for satellite radio without FM modulation or swapping out the factory unit?