<< People call it NOS the same reason they call photocopying Xeroxing and tissues kleenex and cotton sqabs q-tips
the established brand jsut becomes the name people associate w/ it. >>
Car parts are a little different when it comes to the brand recognition thing. When someone is talkinga about parts, they don't say "I just put a Borla on" when they actually got a Bassani cat-back or whatever. People will either refer to a generic term "I just installed an exhaust" or they'll say the specific brand, "Just put a Bassani H-Pipe on".
You start getting into "rice" when you start calling stuff by the wrong name. Local ricer puts a GReddy sticker on his car because he got a new exhaust, but all he actually did was go to Midas and have em weld on some 4" chrome pipe on the back of his rusted out muffler.