The term RICE has been blooown waaaaay out of proportion, there are no true boundaries and definitions that are clear cut. Thus most people say that RICE is a Japanese Import, that's it period, referring to an "Asian" car because of rice. HOwever, this "CULTURE" that you speak of, is not defined by that IMO, the "CULTURE" is defined by people who will buy an economy car(OF ANY KIND) and then only focus on cosmetic LOOKS, usually not much is done to the engine for power, other than SOUND.
For example, you will see tons of CALVALIERS, FOCUS's, ESCORT's, NEON's, that are "RICED" out, I really think that's a horrible term, I mean it really doesn't describe the whole picture, it's used for Japanese Imports, and used for this culture you speak of as well. Unfortunately, heh, there doesn't seem to be another real term for it.
As far as a Japanese Import goes, by all means I don't consider it under the "RICE" movement that's brought out here, such as someone buying a car and making it have a huge WING, with flashing under LIGHTS, and a chubby BODYKIT, but NO POWER modifications...as this it makes it clear that this is done to domestics, and even european imports that we have here(IE: non GTI golf's)
For example, a brand new Honda Civic, or Toyota Corolla(no one even bothers doing anything to those) is bought by the American consumer for reasons other than "ricing" it out. Many just want a decent and reliable economy car, whether it be a mom or an executive(believe it or not I know some very rich pple who drive Honda civics for gas mileage purposes) It's just a practical commuting car, and a good one at that.
Now, having said all this, I believe all cars, that are NOT intended to go fast, BUT are dressed up to look like a CRAZY RACE CAR is "RICE"(again a term that I think that is poorly used nationwide), that includes some OLD BMW 318 with a WHACK paint job I saw some kid drive around the other day.