1969 Chrysler Concept 70X

Chrysler’s Concept 70X concept car featured parallelogram doors similar to those used on today’s minivans. Interior contained a small ultrasonic electronic device that was mounted next to the rear seat speaker. This component swept an area 50 feet to the rear in three zones: left lane, right lane and immediately behind. When a vehicle entered one of the swept zones, a red warning light lit up on the mirror, often giving as much as .04 seconds warning before impact.