I have a japanese car and make fun of the ricers. I agree with GTO. It's the guys who spend $10k on cosmetic stuff and still have a stock motor, but try to drag race people, they give the rest of us a bad name. Street racing is just plain stupid.
I think it may also depend on where you live. Out here where the whole hot rod culture (and ricer culture) was invented, there are a lot of people who do so some serious shade-tree engineering to build truly fast cars. In other parts of the country, you just have wannabees copying what they saw in Fast'N'Furious or some magazine. If these tards are all you see in your area, then it's understandable to make fun of them.
But there are still neanderthals like Chairboy describes, who have a nationalistic or even racist aversion to japanese cars, regardless of the fact that many of them have great engineering and performance.