In my opinion a ricer is someone who has a POS 4cyl and puts a bodykit and a fart can on it and thinks there hot shit. I think if you have a car with a bodykit, rims, and a wing, it better be fast. Otherwise your a ricer.
There's a guy that i know with a DOHC saturn that definantely falls under the term Ricer. He's got a loud obnoxious exhaust and an intake with dual air filters that add's "15 hp". I was talking to him one time and I asked him what all he had done. First thing he said was that he boosted his compression. I asked if he had put different pistons in, he said no. I asked if he had put a different head on his car, he said no. That's when I wanted to kick him in is dumb head and I pretty much ignored him from then on. Guys like that are ricers.
When it comes down to it though, It's your car, it's your canvas. Do what ever you want to it. Your the person that has to drive it. Just don't pull up next to me at a stop light and rev on people who will make you look like a shithead and give import tuners bad rep.