Some concept cars are total flights of fancy, while others have some sort of grasp on reality.

Over the decades there have been thousands of concept cars produced, some of which have reached production (invariably in much watered-down form) while others were far too outlandish to hit the road. And America has long been in the vanguard.

Here we look at some of the American concepts that didn't make it but we wish they had, either because they were technically brilliant or – more likely – because they simply looked fantastic even if they were completely impractical, but we love them anyway: