for my non-NAV, i got a AUX unit on ebay for about 80$, it plugs in the external CD changer port on the factory head unit. that's it, all you have to do is to physically fit the unit and run the wire. I fit ther unit someplace on the passenger side of the AT shifter...a little futher back than the shifter. I run the wire to the shifter area, drilled a whole in the plastic plate, placed the jack there.
can't nav play MP3s from a DVD? If so, i would not bother with AUX probably....
