The 1989 Cadillac Solitaire Concept

The 1988 Cadillac Voyage concept

The 1985 Mercedes Benz Le Mans prototype

The 1981 Ford Cockpit concept (Ghia)

The 1988 Ford Bronco DM-1 concept

The 1988 Ford Splash concept

The 1987 Pontiac Pursuit

The headlight looks like it is worthy of K.I.T.T.

The 1989 Pontiac Stinger Concept

The 1988 Pontiac Banshee

The Pontiac Banshee was introduced in 1988 to provide a glimpse at the high-performance sports car of the future.

The Banshee name first appeared in the '60s as a code name for the forthcoming '67 Pontiac Firebird,

companion to the '67 Chevrolet Camaro.

The 1988 Oldsmobile Aerotech

The 1988 Oldsmobile Aerotech, an experimental high-speed vehicle incorporating the latest in performance technology, (In 1988 that is.) was driven by three-time Indy 500 winner A.J. Foyt to a world closed-course speed record of 257mph (413 km/h). 
It was powered by a specially-prepared turbo-charged version of the Quad 4 engine.

The Aerotech body was designed by GM Design staff and is one of the sleekest vehicles yet developed for a GM car division. The design of the Aerotech includes the capability of adjusting underbody sections to control the distribution of downforce, front to rear.

The 1983 Buick Questor

The Buick Questor was unveiled in 1983, GM's 75th anniversary year.

The Questor demonstrated state-of-the-art electronic systems for future cars,including a laser key entry system and a voice-activated radio telephone.

The 1982 GM Aero 2000

The GM Aero 2000, one of the most aerodynamic automobiles ever developed,

was unveiled in 1982 at the Epcot Center World of Design display.

The experimental four-seater featured sliding doors,

front wheel skirts top-hinged for access to wheels and tires,

and a speed-regulated rear foil to reduce fuel-costly air turbulence.

Many of the design concepts are evident in GM's electric car, EV1.