I think you are making shit up.
I have been around a ton of cars and car people. Rice was never used to describe Asians.
A ford focus with a huge wing? Rice
A civic with a massive ground effects? Rice
A twin turbo Supra with nitro? Tuned.
The ethnicity of the driver or country of origin never came into it, East Coast, West Coast.
Is hoopty racist? No. Neither is rice.