Most people in Japan drive little cars that are classified as "kei", and they have the weakest hp and weight classification. However, they do get the best gas mileage and have the cheapest insurance. These "kei" cars look much like the Scion xB and xA. The Hoda fit is quite popular too! The most popular Nissan in Japan is the Nissan March. On average, you just see the Nissan Cubes and other box cars "drifting" around the streets. Some might have some fancy ground effects or a chrome tail-pipe, but most are plain and very cheap. It's actually rare to see 7's, Supra's or GT-R's driven every-day (of course more frequent than here). All in all, the racing/VIP/drifting/drag racing/show lifestyles are just sub-cultures like we have here. They are by no means the norm and are often frowned-upon by authorities and average everyday people (just like here).
Yes I love my GT-R, not because of JDM status, but because it is a fcuking blast to drive and tinker with. I wish to God they sold it here from the beginning, for my bank account would be much happier! Sure the RHD factor is a novelty that attracts attention (mostly in and of itself), but the car is fun to drive. There are many cars here that are fun, too! I.E. Supras, Type Rs, S2ks, 7s, etc.
It's a free country (sort-of), so if having "JDM" parts on your car makes you happy, then cool. Just remember that what you think is "JDM", may in fact be "JDM", but it's not what your average run-of-the-mill Japanese remotely cares about!
Sorry for the long rant.