Wreckless - The Yakuza Missions cheats and cheat codes for Gamecube

Unlock Everything 
At the Cheats screen highlight Unlimited Time and hold L, R, Right, and Z

Gold rank on all missions
Highlight the "Unlimited time" selection at the main menu, after hit
L + R + Right + Z as the game loads.

AUV: Finish mission A-9
Best car: Finish mission B-1
Dragon-SPL car: Finish mission A-1
Missions A-2 to A-4: Finish mission A-1
Missions B-2 to B-4: Finish mission B-1
Music test at the options menu: Finish all twenty missions
Tank 90: Finish mission B-8
Tiger-SPL drives: Finish mission A-8
Yakuza car: Finish mission B-9

Change view
Hit Down to cycle through different screen effects during a game and replays. 
To unlock more effects, Finish missions A-9, A-10, B-9, and B-10.

Additional hidden vehicles
Locate the "?" on the map in the 4 different missions 
to find the secret vehicles.