Plymouth Voyager 3

Part of the car's aerodynamic design featured a glass roof.

The rear wheels of the cab were hidden (notice on image) when it was all in one piece.

Each segment of the vehicle contains its own four-cylinder engine, which are electronically-coordinated to deliver power independently or in concert.

[1] The Voyager 3 was credited to Chrysler Designer Tom Gale (who also penned the Dodge Viper and Plymouth Prowler) by one source that also called it "the worst concept car of all time".

[2] This concept car debuted at the 1990 Chicago Auto Show walkaround video in 1990.