Installing the OEM Nav unit in a vehicle that didn't come from the factory equipped that way is not a viable option. Here is what I posted in another thread:
"I have looked and researched this EXTENSIVELY for my wife's Aviator. A word to the wise...don't consider adding the OEM option. I know the wiring is different between the Aviator and the LS, but there are still enough similarities that make this a non-starter unless you absolutely have to have the factory unit. Here are some things to think about that I found out on the Aviator...
You will need a ton of parts. You are looking at a head unit, a dvd drive, a module, an antenna, and a rear view mirror just to start. Then you will need the factory wiring harness. Adding your own is not really an option. There are shielded wires, twisted pairs, etc. that need to be incorporated in the sysytem. I even asked Painless Wiring and Howell if they would be interested in building me one and they both turned me down. Next, you will need to rewire the factory stereo system. The speakers on my Aviator are powered differently with the Nav. One system powers them with the amp, the other doesn't and I can't remember now which is which. You will need to wire and install the NAV rear view mirror. It has a microphone that you need or the unit will throw a trouble code. And that is just what I can think of off the top of my head.
In my opinion, this is just not a viable swap. The unit shown here is very nice. Pioneer makes a fantastic couple of units (AVN1 ?) that everyone raves about. A dealer told me he could even install a unit that kept the function of the steering wheel controls. You could install the Pioneer yourself for under $2000 easy if you shop for it. The factory unit couldn't touch that. The wiring harnesses alone were hundreds of dollars"
These guys on eBay who are advertising their head units as a way to add Nav to a car are lying and fraudulent...or just plain ignorant. It just doesn't work that way.
