you'd be much better off buying an aftermarket double DIN head unit (pioneer, kenwood, etc) that has navigation. the factory nav system is tied into the head unit (i believe only the bose one) and there's so much going on with that setup that you pretty much have to get it from the factory or not at all. you will get better sound quality and more options (ipod adapter, navigation, bluetooth, etc) for less money doing it this way. yes it won't have that factory look but it will look pretty good. i have a pioneer double din and i love it, can't recommend them enough
