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Gilley wrote:If you want navigation you're going to be better off replacing the radio with a double DIN unit with navigation. You can't just add the factory navigation and plug it into the stock harness. The harnesses are different between navi cants and non navi cars. It can be done with a lot of schematic reading and wire hacking.
My 03 sedan has 172k on the motor and automatic tranny and it still runs strong. I replaced the valve cover gaskets and the spark plug gaskets (only on one side) 1300 miles ago and the top of the motor was still really clean.
This is just a partial diagram of everything needed to do an OEM navi install. As mentioned above, if you want an in-dash solution, your best option is to replace the head unit, otherwise just get a portable unit and call it a day.