In 1970, the average car had only $25 worth of electronics. By 1981, the average car electronics had risen to more than $1,000 per car, and by 1996 to more than $1,500 per car. And the number is still rising.
Today, a vehicle’s computers operate almost every system — air conditioning, radios, airbags, alarm systems, anti-lock braking systems, traction control, ride control, cruise control, electronic digital and analog instrument panels, automatic transmissions, and last but not least, emission and engine controls.
Other than a radio, auto air conditioning is the most popular new-car accessory today. Over 75% of all pride and joys roll out of the showroom with "factory air." What's more, each year a half-million used cars have air conditioners added. 
