After you complete level 2 the first bonus game will start. A Mad Gear member has left his car parked outside a gas station, so do what anyone would -destroy it! Simply keep hitting away at the car's "break points" until all 3 points are destroyed. Haggar can usually make mincemeat of the car within seconds by using the iron pipe which is at the front of the car. Destroy the car within the time limit for the most hilarious moment of any scrolling beat 'em up ever: the famous "OH! MY GOD!!" part.
Once the Industrial Area (level 4) has been completed, the second bonus game will come up. This time you have to work your way though a glass factory smashing glass panels as you go along. You must hit them in the center to destroy them otherwise they will spin around and hit you, wasting time. Destroy them all within the time limit for a large points bonus.