Try this one:
A)Beat N.Oxide's Final Challenge in Adventure mode.
B)At the victory square, when it shows your character in victory stance, hold L1 and R1 while pressing Down, Left, Up, Up, Triangle, Circle, and X to continue to the epilogue.
C) Usually, when it says "Unfortunately, the unicycle was a poor choice for the alien, and the resulting accident was too gruesome to detail here" it will say " Oxide raced _____(player name) again...."
D)Go to Oxide's boss garage. The eyes on Oxide will look red, and he will be clenching his fists in anger. Drive into his garage, and listen carefully. You will hear, " This time you lose."
E) He starts the race two lights before you this time, and drops four potions behind him(juiced up) His kart glows a light orange when you're close to him, and taunts like "Say good-bye" and "Hehehe" are replaced with "Eat asphalt!" and "Looser".
F)There is an extra jump that isn't normally there. Aku Aku will appear in front of you at the long jump. "Crash, take the jump to the right," it will say. Take it, and Oxide will say "Nooooooooo" (the jump is only available on final lap) and you beat him instantly when you take it. He says, "I can't go to Gasmoxia NOW!" and a bonus race where you have to escape the exploding Oxide Station.
G) Have fun with N.O.
If you see me posting, it's because I've been asked to. Which I guess would mean I'm taking requests.