I'm quoting this off a site I found....
The term "Rice-Boy" is meant to be a derogatory term. But not racially derogatory. Some people might say that regardless of what this disclaimer says, it makes Asians look bad. Well, I hate to break it to these people but asians are not the only people on this planet who eat rice. Everyone eats rice. White people eat rice. Black people eat rice. Native Americans? They eat rice. Europeans eat rice!! And, if you open your eyes, you might notice that a whole lot of the rice-boys out there aren't even asian! The "rice" really refers to their cars. It's not about their race, it's about their attitude!
If you want to read more of a definition check out his page.
http://www.riceboypage.com/what_is_riceboy/
I think it's a great site and makes some really valid points.
§am.