correct.
indeed. I import a lot of specific audio stuff for them as it is and most of it sits and gathers dust. now in comparison to other models most of that moves easily.
depends. most people ASSUME that things are the same between the car (G35,350Z) and in some cases they are not. audio/electronics is point and case. they look the same but its not.
as for lobbying. supply vs demand - no demand so no supply. give it a few years once these cars age a bit and things will be come more readily available.
agree with the point of USDM items being cheaper than JDM. I get this same problem in my industry.