Cheat mode:)
Remember no money can be earned in Road Rage mode and cheats will only work for the next gaming experience (once you return to the main menu all codes will be deactivated).

Unlock Horizontal split screen:)
In the options menu push and hold L1 + R1 and push Square(4) . A sound will indicate that you have entered the code correctly.  The screen will be split horizontally instead of vertically in two player mode.

Unlock Alternate views:)
In the options menu push and hold  L1 + R1 and push Triangle(4). A sound will indicate that you have entered the code correctly. Additional views will be unlocked at the pause screen. To unlock another set of views, hold L1 + R1 and push Triangle, X(3) at the options menu.

Unlock Nighttime:)
In the options menu push and hold  L1 + R1 and push X(4). A sound will indicate that you have entered the code correctly.

Unlock Flat characters:)
In the options menu push and hold  L1 + R1 and push Circle(4). A sound will indicate that you have entered the code correctly.. All the people (except the character you chooseed) will be flat.

Unlock Show collision lines:)
In the options menu push and hold  L1 + R1 and push Triangle(2), X(2). A sound will indicate that you have entered the code correctly.

Unlock No map display:)
In the options menu push and hold  L1 + R1 and push Square, Triangle(2), Circle. A sound will indicate that you have entered the code correctly.

Drive red brick car:)
In the options menu push and hold L1 + R1 and push Triangle(2), Square, Circle. A sound will indicate that you have entered the code correctly.. Remembeer that this car is controlled by Homer and is small fast, and heavy.

Drive as Smithers in Mr. Burn's limousine:)
In the options menu push and hold L1 + R1 and push Triangle(2), Square(2). A sound will indicate that you have entered the code correctly.

Drive Nuclear Bus:)
In the options menu push and hold L1 + R1 and push Triangle(2), Square, X. A sound will indicate that you have entered the code correctly.

Special car moves:)
In the options menu push and hold  L1 + R1 and push X, Triangle(2), X. A sound will indicate that you have entered the code correctly.. Press and hold Gas + Brake + Handbrake while steering left or right while in mid-air to execute the Road Rage Roll. Hold Gas + Handbrake while stationary, then release Handbrake to execute the Speed Boost.

Time trial mode:)
In the options menu push and hold  L1 + R1 and push Circle, Triangle, Square, X. A sound will indicate that you have entered the code correctly. There are no passengers, pedestrians, or traffic I this mode. Push Horn to start, stop, and reset the timer.

Slow motion:)
In the options menu push and hold  L1 + R1 and push X, Circle, Triangle, Square. A sound will indicate that you have entered the code correctly.

Halloween mode:)
In the options menu push and hold L1 + R1 and push Triangle(2), Circle, X. A sound will indicate that you have entered the code correctly. Choose any character to unlock Bart in a Frankenstein costume. Alternately, set the system date to October 31.

New Year's Day mode:)
In the options menu push and hold  L1 + R1 and push Triangle(2), Circle, Square. A sound will indicate that you have entered the code correctly. Choose any character to unlock Krusty in a tuxedo, Alternately, set the system date to January 1.

Thanksgiving mode:)
In the options menu push and hold L1 + R1 and push Triangle(2), Circle(2). A sound will indicate that you have entered the code correctly.. Choose any character to unlock Marge in a pilgrim dress. Or set the system date to the third Thursday in November.

Christmas mode:)
In the options menu push and hold  L1 + R1 and push Triangle(2), Circle, Triangle. A sound will indicate that you have entered the code correctly. Choose any character to unlock Apu in a Santa costume. Or set the system date to December 25.

Disable all active codes:)
In the options menu push and hold  L1 + R1 and push Start(4). A sound will indicate that you have entered the code correctly.

2 Money Bonus:
When you play the game, sometimes when you pick someone up, you might get a Road Rage bonus or a Safe Trip bonus. Safe trip is to not crash into 3 cars, Road Rage is to destroy stuff. Do road rage to get 1000 money, do safe trip for 250 money.
User Cheat by martinbooth

Car built for Homer:)
After finishing all ten levels in mission mode you will unlock the car built for Homer.

Extra time:)
To get +2 seconds, hit the bus stops booths that have Mr. Burns' picture on them.