Navigation CD ? DVD

I just bought a 2003 Navigator with the factory navigation system. WHere can I get the dvd to update the maps? There are a bunch on Ebay, but I dont know which one I need..
Thanks

I would call Ford for compatible issues. They'll tell what revisions are for your serial number.

You might be able to find some information on the MotorCraft site under publications. (http://www.motorcraftservice.com/vdirs/SPubs/default.asp?TYPE=OWNERGUIDE&pageid=oghome&gutsid=spubs_serv_all_new&YEAR=2003&VEHICLE=Navigator)

yeah just go to ford and ask or the manufacturer of what ever your navigation is called