I think the term 'JDM' comes from the States, Australia and Europe, where most of the japanese cars that end up over there are the nanna spec standard models.
New Zealand has the benefits of its vehicle import laws/standards that car dealers can pretty much import any spec of a vehicle that they want.
Other countries are a little stricter on these 'go-fast' versions, so they dont get some models/specs of cars on a regular basis.
As an example, try and find a AE111 in Australia that hasn't been specially imported by someone. I was on an Australian car website/forum and posted up some pics of my own AE111, and most of there users had no idea of what it was, or any info on the engine/driveline etc. For some, it was the first time that they had seen one. LOL!
So when these less fortunate countries get these 'nanna' spec models to drive, the ones that want to modify them either go for aftermarket parts. Most of which are just copy's of standard parts on the higher spec models. They buy them up like hot-cakes and the aftermarket parts importers are making sh#t-loads of money from these poor unfortunate types.
So,
'JDM' spec parts or vehicles are basically anything that is available in Japan or any other country that has less strict importation laws/regulations.
It is a marketing ploy by aftermarket parts importers, pure and simple.
Your Opinion Means 1/16th Of Stuff All To Me So Dont Bother Arguing With Me About It As I Just Dont Care.
Thank-You.