While a police car may look like any other type of car with only a few exterior modifications, most cars used for police duty are modified heavily inside and out for maximum strength, performance, and maneuverability. The types of modifications for a police car will depend on the car's purpose, as some police car models are designed for normal patrol use, while others are designed for emergency situations and high speeds. Most cars will feature specially designed back seats that can safely contain a detainee. Light bars are the most common and noticeable modification on these cars, and they are used to warn bystanders of the officer's presence.
The light bar is mounted on the top of the roof in most cases, and the lights flash brightly when in use to warn passers by of the presence of a police officer. The lights can be used as a warning system for motorists as well, particularly at night when visibility is poor. Most police car models also feature a brush guard and battering ram mounted on the front of the car, which can be used for many emergency situations. This specially designed bumper is effective at forcing vehicles off the road, so it is commonly mounted on traffic cars, which are heavily modified for speed and maneuverability so it can track down other speeding vehicles on the road. The bumper can be used to enact what is known as a pursuit intervention technique, or pit maneuver, which forces a fleeing car off the road with a nudge from the specially designed bumper.
The engines of the police car may be modified, though more common modifications include cooling systems that prevent overheating during long distance use as well as long idling times, more responsive suspension for maneuverability, and upgraded electronics systems meant to handle the extra burden of light bars, command consoles, and other electronic devices commonly used by police officers.
The trunks and other panels of a police car can be modified to become a weapons locker for guns and other weapons that are not used daily by an officer. These weapons are usually tactical weapons for emergency situations, and they need to be otherwise secured when not in use. The types of weapons carried in the car will vary according to the purpose of that car and the officer operating it, and some police cars are larger vehicles such as sport utility vehicles that can carry more specialized equipment.