The latest example of "beautiful spindly things that will never be built", the "ThisWay" bike by designer Torkel Dohmers, is imagined to be built of flax fiber and carbon fiber with a clip-on battery charged by rooftop solar panel for assisted recumbent cycling.
Had it not first caught my eye as wooden (it is not) and then intrigued me by color choice (it's a very ranch-style '60s shade) I probably would not have linked to it. Caramel might look good on plastic.
You know what vehicle some Scandinavian design needs to reimagine in sinuous simulation? The Big Wheel. I'd ride a modern version of that around town.