I know it's not plug and play.. Dont worry about the money (cost).. Is there any valuable information about how to so it??
Does anyone have the wiring diagrams for both (Navigation/ without Navigation)??
From where should i start??
You need to remove the wiring harness for the entire electrical system. Different harness. Don't know how much it costs. This entails guttiing the interior, dash, seats, liner, everything. Then you need to by new dash pieces, then NAV unit, and then run the new harness.
Should take about 40 hours of work and cost $3000 or so in parts. Or you could buy an Alpine, Clarion, etc. for a grand and install in 2 hours. These have better NAV computers and you can take it with you to your next vehicle. It would fully integrate with the steering wheel controls, and the sound system, and it would be a much better unit than the Fake Bose made by Panasonic that comes with the Bose system. You could even do a DVD with it from the dash and run it to the stock DVD screen for no additional cost, add headrest DVD screens for a couple hundred each, watch DVD from the front seats, not fill up your center console with a DVD player, etc.
The only funtion you wouldn't have is viewing the AC settiings on the screen, and the trip computer, but the Alpine and others have other stuff you wouldn't have with the stock system. One for example is you could hook it up to an alarm, and have the car call you if it goes off.
BTW, I haven't heard of anyone doing this in a Mada or Titan. The aftermarket is common. In fact, many people specifically choose not to get the stock stuff knowing they are going to upgrade for less with aftermarket stuff. And I was a pro installer for years and wouldn't want to try to do this myself. I'm sure I could do it, if I wanted to burn several weekends and have the mada sit in my garage in pieces for a month.