Don't be afraid to use the Supercop (invincibility) mode to plow through the cars of innocent bystanders. You won't lose points for your cavalier attitude, and you can save precious seconds of pursuit time.
Should you find your car on fire, simply smash through a fire hydrant to extinguish the flames with a jet of water.
Rams are best executed on the side of the felon's car. Try to position your car at a 45 degree angle to their broadside before ramming.