All starting locations in patrol mode
Go to the title screen and press Down, Up, L2, L1, X, Triangle, R2, R1.
Level select
Go to the title screen and press Down, Up, Left, Right, X, Triangle, Circle, Square.
Mission 12, Nosey news van
To successfully pass the mission, lose the van and disable the perp. To earn a commendation, lose the van and return to the rendezvous point within 90 seconds and suffer 50% or less damage. The quickest way to loose the van is to just keep circling around a city block until he just looses sight of you then quickly get back to the stakeout location and then go after the bad guys.
Mission 20, Final showdown
To successfully pass the mission, disable the perp. To earn a commendation you must suffer 50% or less damage, 90% or higher shooting accuracy. Try to stay close behind the limo and use the rocket launcher whenever you have a clear shot. Try not to get too close or the blast from the explosion will damage you car as well. Also, beware of firing the weapon too close to civilians!
Unlock everything
Press Left, Right, L1, R1, Circle, Square, R2, L2 at the main menu.