Derives from a combination of (Subaru) wrx and (Mazda) rx8 = Any sportscar whose name you can't remember, especially if it is Japanese.
BOB: I can't believe it! Some Jap-Crap Rice Rocket
blew away my Mustang last night!
MIKE: What was it?
BOB: I don't know Japanese! Some wrx8 or something!
MIKE: Come on. It's not THAT surprising! You only have a V6 in that thing!
BOB: WOW! I could've had a V8!