I may be able to get my hands on a stock Navigation head unit. I currently have a 6-disc changer with Sat. radio. Has anyone done this install before? Will I need to install a new GPS/Sat radio antenna or will the one for the Sat radio work for the GPS too?

 

you will need to install a gps antenna. Their is a plug on the back of the nav. unit.I think it is pink. it mounts under the dash. I bought a nav. for mine and switched it and it is very easy to do. If you do a search their is a thread with some good pics.