The more informed automotive crowd like us don't really associate the term Ricer as racist, but sadly to others, there is a racial connotation to it and has been used as a slur, mostly in my experience from white dudes who automatically associate asians with ricers in their minds. I've personally confronted someone who called a group of us exiting ford explorer of all things that and why they called us ricers....the answer was because we all eat rice. Upset me a bit because in their little minds, the term ricer was no different than the N word.
When used on vehicle forums though, I don't find it racial as we all know what the term really is referring to.