<P> Vehicle audio is equipment installed in a car or other vehicle to provide in - car entertainment and information for the vehicle occupants . Until the 1950s it consisted of a simple AM radio . Additions since then have included FM radio (1952), 8 - Track tape players, Cassette Players, CD players (1984), navigation systems, Bluetooth telephone integration, and smartphone controllers like CarPlay and Android Auto . Once controlled from the dashboard with a few buttons, they can now be controlled by steering wheel controls and voice commands . </P> <P> Initially implemented for listening to music and radio, vehicle audio is now part of car telematics, telecommunication, in - vehicle security, handsfree calling, navigation, and remote diagnostics systems . It is also used to create fake engine noise . For the 2015 Ford Mustang EcoBoost, an "Active Noise Control" system was developed that amplifies the engine sound through the car speakers . A similar system is used in the F - 150 pickup truck . Volkswagen uses a Soundaktor, a special speaker to play sounds in cars such as the Golf GTi and Beetle Turbo . BMW plays a recorded sample of its motors through the car speakers, using a different samples according to the engine's load and power . </P> <P> In 1904, well before commercially viable technology for mobile radio was in place, American inventor and self - described "Father of Radio" Lee de Forest did some demonstration around a car radio at the 1904 Louisiana Purchase Exposition in St. Louis . </P> <P> Around 1920, vacuum tube technology had matured to the point where the availability of radio receivers made radio broadcasting viable . A technical challenge was that the vacuum tubes in the radio receivers required 50 to 250 volt direct current but car batteries ran at 6V . Voltage was stepped up with a vibrator that provided a pulsating DC which could be converted to a higher voltage with a transformer, rectified, and filtered to create higher - voltage DC . </P>

When was the first radio put in a car