The auto-centric Jalopnik recently compiled its list of The Ten Craziest Concept Cars of All Time, which includes a couple of wonderful midcentury designs that sadly never made it into production.
Unfortunately, they squandered slot number 9 on the fictitious, though slightly Googie-esque, 1991 Powell Motors Homer, rather than awarding it to something like the 1958 Ford X-2000 with its Enterprise-like nacelles or the Ford Volante of the same year, with its triple ducted fans that powered intercity flight (both pictured here).
Still, they did recognize the atomic-powered Ford Nucleon (1958 was apparently a great year for Ford's design team), as well as Buckminster Fuller's unrealized 1933 Dymaxion. Have to give them credit for that.