It originally came from the fact that asians eat a lot of rice, and import cars are made mostly by asian companies. I don´t really know exactly where and when it came around though. Personally I think the term is stupid but that´s me.
I am sure it came frome the term Rice burner, which was/is used to describe vehicles of Asian origin. And since you see a lot of Asian cars running around with big spoilers, and huge fart cans, they are refered to as being "riced out." So anytime someone puts a fart can or spoiler on any car it could be concidered as putting "Rice" on their car since they are making it "riced out." I have another term for cars that are "Riced out," that term is "A huge waste of money." Anyone who pays over $150 bux just for a muffler is crazy. They should just give me their money so I can use it to fix my car.
RICE-afficionados like to claim that RICE stands for "Racing Import Car Enthusiast" which has a much nicer ring to it. The obvious logic flaw is the word RACING, which has nothing to do with oversized wings, 5" LED-tipped exhaust tips, neons, etc etc.
Pimp: I guess your refering to my Scort b/c when I bought the muffler two and a half years ago, it was 200.00. :-D But its on my Scort so I don´t qualify right? :-D I don´t think my car is a big waste of money. ;-) :-D