Unlock Bat and Pork Choppers:
Beat all of the rescue missions, to unlock the Bat and Pork helicopters.
Unlock Chase Car Mode:
Earn an A rating on all missions and an S on the Bus Chase, to unlock "Chase Car Mode"
Unlock Disaster Mode:
To unlock Disaster Mode, achieve a S rating in Final Rescue Mode.
Unlock Final Rescue Mode:
To unlock Final Rescue Mode, earn an S rating with the Sports Car.
Unlock Time Attack Mode:
Finish all the chase missions to unlock Time Attack mode