One of the last cars designed by Harley Earl, the 1956 Cyclone concept was a test-bed for futuristic styling and technology, according to Wikipedia. The design was heavily inspired by the aviation and rocket designs of the 1950s.
The Cyclone was built on a 104-inch wheelbase chassis and featured a front-mounted 390-cubic-inch V-8 engine, rear-mounted automatic transaxle and an all-wheel independent suspension.
A unique design was the engine exhaust that was ported out just ahead of the front wheels. It also featured a radar-operated collision avoidance system, with the radar sensors mounted in twin “nose-cones” on the front of the car.
The bubble-top canopy, silver coated for UV protection, automatically opened along with the sliding electrically operated doors. The canopy could also be stowed in the rear compartment, where it rested on a special air-bag base.
The original design of the Cyclone included larger tailfins (similar looking to the 1959 Cadillac lineup), adorned with the logo of the General Motors Air Transport Section (GMATS). The fins were reduced in size in 1964 (and the GMATS logo removed) to look more like the 1963-64 Cadillac range.