I am wondering the same thing. I have an 05 4.4i equipped with Sat radio, and VCF. I want to do a NAV retrofit but I am not sure what else I am going to need besides the screen and the dvd player in back.

There is a blue plug tucked behind my CD changer with a jumper plug conected to it. Is this for the nav?

I was thinking that this car was prewired is this true?

What else to I need? I looked at the posts on the home page but they all were upgrades from previous year models...

Thanks..