when was the first radio put in a car
Vehicle audio 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. [3]
Remote keyless system Keyless remotes contain a short-range radio transmitter, and must be within a certain range, usually 5–20 meters, of the car to work. When a button is pushed, it sends a coded signal by radio waves to a receiver unit in the car, which locks or unlocks the door. Most RKEs operate at a frequency of 315 MHz for North America-made cars and at 433.92 MHz for European, Japanese and Asian cars. Modern systems since the mid-1990s implement encryption as well as rotating entry codes to prevent car thieves from intercepting and spoofing the signal.[3] Earlier systems used infrared instead of radio signals to unlock the vehicle, such as systems found on Mercedes-Benz,[4] BMW[5] and other manufacturers.