...in 1974, when all new cars and light trucks sold in the United States featured DOT-mandated interlocks that prevented engine starting unless driver and front-passenger belts were fastened.

http://search.yahoo.com/r/_ylt=A0oG7l1f4...gate-scandal-2/

Mine,while still on there,has been disconnected on my car...guess it just depends on how original you wish your car to be.