The way I have always understood the etymology was that Asians initially, put over the top, cosmetic crap on their cars, and it was called rice because it was what, stereo typically, only Asians ate.
Further on from that, it became the word for the stuff added on, not the person or type of car that was involved
Moral of the story is, don't put crap on a euro car. Ze Germans didn't spend hours and millions in development for you to ruin it with something thought up by a douchebag.