Instructions
Select an event in which the "Crashbreaker" mode is available. In the single-player game, the "Crashbreaker" mode is available in "Crash" events and specially labeled "Crashbreaker" race events.
Fill up your boost meter in "Crash" events by driving your car into concentrated traffic. Aim for large vehicles and big-rig trucks that can block the road and collide with oncoming traffic; moving vehicles that crash into vehicles destroyed by you (directly or indirectly) increase your boost meter.
Fill up your boost meter in "Crashbreaker" events by attempting dangerous stunts or forcing your rivals to crash. You can drive on the wrong side of the road, drive close to oncoming vehicles or "power-slide" around corners (tap your breaks as you turn around a corner) to increase your boost meter. Causing your rivals to crash also will increase your boost meter.
Activate the "Crashbreaker" mode (by pressing the button indicated on-screen) when you have crashed into another vehicle and your boost meter is full. You can slightly nudge your vehicle in any direction before you activate the "Crashbreaker" mode by using the directional joystick.