Ipod or MP3 player hook-up

Has anyone had any luck finding a way to connect a line in or Ipod to the factory unit. (i don;t really want to do the FM unit) I have a 06 Gransport with a Becker CD changer. I am looking for a simple way to hook up a ipod or Mp3 device without making major mods to the factory unit. I heard of a way to use the CD changer connection to hook up an ipod but have not heard of anyone actually doing it. sound quality..anyone???

thanks fsujohn