6 disc cd w NAV 88972143 or 88971499

[suz_an]

Can anyone tell me what the differences are -0r where I might find info detailing differences on the original radios AM-FM-stereo-6-disc CD player-Nav "U1A", ID 88971499 AM-FM-stereo-6-disc CD player-Nav "U1A", ID 88972143 My 04 cd player is defunct, looking to find something w navigation, and add a direct usb connect if possible... looking at used and new.thanks