I'd go along with the factory look until I changed the speakers in mine. I put in some decent Pioneers... turned it up, sounded better, but really muddy. Went and put my Alpine in that I had in my merc, I damn near cried when I figured out how much clearer it was! I went like 3 months before switching head units. I could never understand why Ford always wusses out on creature comforts in their vehicles. I haven't heard a factory radio yet, that $300 at walmart couldn't blow away. I mean, that's downright embarrasing. So as far as Nav goes, yeah you can have it look stock, but it's gonna sound like it too. Of course, if you listen to AM radio, you're probably alright!