and receiver, which make it easier and cheaper to install them. Built-in audio intercoms (one-way or two-way) are used in addition to the camera system for communicating with a spotter outside the vehicle - common when backing large trailers or launching boats. Night vision cameras use a series of infrared lights for backing in the dark, when the positioning or the intensity of the vehicle's white reverse lights are insufficient for this purpose. Portable or semi-permanent all-in-one camera systems, also known as dashboard cameras or dashcams, are typically sold for vehicles that don't have displays permanently installed in the dash. Such systems consist of a small portable screen that can be affixed on the dashboard or on a rearview mirror, and a length of wire to reach the cameras, including a backup camera. Some backup and rear cameras are connected to displays on the rearview mirror and are used in vehicles to detect activity behind the car to "avoid the tooling, software, hardware, and testing costs associated with integrating the display/feature in other areas of the vehicle." License-plate-frame versions permit installation without any permanent vehicle modifications. Custom cameras: brake light cameras are combination devices that contain a camera, while still illuminating as a brake light. Some backup cameras also use a combination of LEDs surrounding the camera lens to illuminate the surroundings while in use. History The first backup camera was used in the 1956 Buick Centurion concept car, presented in January 1956 at the General Motors Motorama. The vehicle had a rear-mounted television camera that sent images to a TV screen on the dashboard in place of the rear-view mirror. Later the 1972 Volvo Experimental Safety Car (VESC) had a backup camera. However, the camera did not make it into the following Volvo 240 model. The first production automobile to incorporate a backup camera was the 1991 Toyota Soarer Limited (UZZ31 and UZZ32), which was only available in Japan and not on U.S. counterpart Lexus SC. The Toyota system used a color EMV screen, with a rear-spoiler-mounted CCD camera. The system was discontinued in 1997. In April 2000, Nissan's Infiniti division introduced the RearView Monitor on the 2002 Infiniti Q45 flagship sedan at the 2000 New York International Auto Show. Using coloured onscreen guide lines as a parking distance parameter, the RearView Monitor operated from a license-plate-mounted camera in the trunk that transmitted a mirrored image to an 7-inch