I have a 2000 DTS with the Bose system (non navigation), i have been seeing alot of factory navigation units out of 2000 DTS's and etc, the pin on the back looks the same, but if i get the navigation radio unit, is their anything else i have to purchase, or is everything built into the unit itself? how can i make this conversion? Thanks

Cadillac nav systems are very rarely plug and play, dealer will have to program radio to see if it will work. You may get lucky or have aquired something to resell.