Update....I now have a factory nav unit in my Sport Trac. I bought the radio/nav from radiosandmore.com and they sent me the gps antenna and the dvd. I did have to get the Ford Dealership to program the unit for 50.00 bucks. Everything works perfect. I did go ahead an had them to turn on the sirius option just in case I wanted to install that unit later. It cost me $1,500.00 bucks for the whole deal which isn't bad since if books for $2,500.00 sticker not that any one would pay sticker.