Hey pep,
I got a 09 g37x with out backup camera and non Nav. Was thinking of converting it to nav with camera. I would be buying the Navi system with trunk lid with cam. Any thoughts about whether this would work out or not? Do I need any special harness for nav system?

 

You'll need the wiring unfortunately. There have been members here that have bought a navi harness and dissected the NAVI wiring from it and retrofitted to their base models. Not an easy task, especially if you lack wiring skills.

Your best bet is to find a donor from a yard and pull the necessary all together as most cashiers can work out a good deal.

 

What do you want to gain?

The swap is not for the inexperienced. You would need the entire system (headunit, display, switch assemblies (both), various misc. items, and- more importantly (and difficult to obtain)- wiring.

Keep in mind that you can only go as far as a 2015 system. The "dual screen 'In-Touch' system" will not work.

If all you want is a backup camera, there are far cheaper, easier-to-install, better quality options available.