GIMMIE

On the Main Menu, open 'Options', then 'Enter Name' and then change the name to GIMMIE (all caps). You'll normally get a message saying that saving is disabled. 
With this code you'll have all characters, all championships and all tracks unlocked in Time Trial.

Woutt64

Cartoon Network Racing (DS)

Death Rally

Townsville Raceway

Middle of Nowhere

Strange Alien Race

Cross Townsville Traffic

Box_munchies_93

Courage

Chicken

Weasel

Johnny Bravo

Dexter

Blossom

Buttercup

Bubbles

I.R.Baboon

Muriel

Suzy

Mojo Jojo

Mandark

Eustace

Dee Dee

Professor Utonium

Bunny Bravo

Red Guy

Normal

Souped-Up

Soupered-Up

Flipped-Out

Character Used

Kart Speed

Cartoon Network (Misc)

Cyberscore

IL Leaderboard Layout

Incorrect Submissions

Speak About Run Here

DeSmuME emulator okay?

MrKepya

ChillCat

kotzuki

slipperymac