yea IIRC, to keep dual climate you have to de-solder the dual button from your old A/C controller and solder it onto the JDM one that came with the double-din

and, as for the N2 not using the grounding method, i guess this is theoretically possible since the AVIC units have sensors to measure speed, acceleration, lateral G force, etc etc for the on-screen performance meters... so they could be using the input from the speed sensor to determine if you're moving...

 

Its a "safety" thing. You can get sued and prosecuted if you get into an accident deemed your fault with a movie on. They were even trying to put one poor guy in Alaska in jail over a movie playing after he got into an accident.