See https://www.urbandictionary.com/define.php?term=rice

Race Inspired Cosmetic Enhancements. (R.I.C.E.)Parts put on cars to make them look fast, when they have no internal tuning, and are actually slow as hell. Parts usually consist of excessivley angular bodykits, large rear spoilers, neon, sponsor stickers, chrome rims, fake "coffee can" exhaust tips, and loud, annoying paint jobs and/or vynils. Sometimes parts are do-it-yourself installed and are basically duct taped to the car. Most commonly known for being done to Honda Civics, but can also be done to slow domestic vehicles, such as a Chevy Cavalier, etc.

In the common vernacular where I live it's generally meant as a pejorative.