Nah, I don't buy it. The posted description above simultaenously claims the following:
1) "Rice Boy" is in no way a comment on the actual ethnicity of the driver or owner of a given car.
2) "Rice Boy" is in no way a comment on the fact that a car is an asian import, because it applies to all cars, even domestics.
Thus I can't see how substituting a word like "Cigarillo" or "Shoe" or "Rectangle" could be any less logical or have any less basis in reality than the word "Rice" given that, by the criteria in the definition posted above, it isn't based on anything. I mean, if it isn't based on either of those critera, one could conclude it's just the product of lazy thinking.
IMHO it either makes no sense, or definitions like this are symptoms of back-pedalling...
I have a word I use when I see a 4 foot Supra wing on a Cavalier or Civic DX - "Idiot".