At the 'Pause' menu use the D-Pad to enter these codes to enable the effect. To disable model change codes reenter the code in again. You'll know if you've entered the code correctly because you will hear glass smashing as confirmation if it's a model change code and a cat noise if it is a traffic code. If there is no confirmation sound when you enter a code press 'Start' twice to exit and then reenter the 'Pause' menu.

Unlock Model Change - Vending Machine 1:
Press X, Y, X, Y, Up, Down, Left, Right.

Unlock Model Change - Vending Machine 2:
Press X, Y, X, Y, Up, Left, Down, Right.

Unlock Model Change - Ice Machine:
Press X, Y, X, Y, Left, Up, Right, Down.

Unlock Model Change - Modern Phone Booth:
Press X, Y, X, Y, Up, Right, Down, Left.

Unlock Model Change - Potted Plant:
Press X, Y, X, Y, Up, Down, Right, Left.

Unlock Fast Traffic:
Press Right, Up, Y, Y, Up, Right, Down, Up, X.

At the menu that allows you to choose Metropolis or Fortress of Solitude when you are loading a game press Up, Right, Down, Right, Up, Left, Down, Right, Up.

Complete the following tasks to unlock the corresponding trophy.

Unlock Globe Bowling Trophy:
Pick up the Daily Planet globe

Unlock Outstanding Valet Trophy:
Pick up 500 Cars

Unlock Bizzaro Unchampion Trophy:
Complete ALL Bizzaro mini-games

Unlock Kitten Finder Extraordinaire:
Rescue ALL 100 Kittens

Unlock Meteor Mayhem:
Complete the 1st level of the game

Unlock Photo Finish:
Defeat 500 enemies

Complete the following tasks to unlock the corresponding costume.

Unlock Golden Age Superman Costume:
Save Metropolis from the tornadoes

Unlock Pod Costume:
Defeat Bizarro