Here is a Velomobile on the Behance Network. It is a two seater velomobile that has four wheels and uses tent like construction. It uses a soft skin type shell stretched over the vehicles frame. Since this is basically how aircraft were constructed way back in the early part of the twentieth century, one wonders how hard it would be to market a velomobile like this. It could very easily be aerodynamic, waterproof and cheap to construct. It might even be possible to fold up and remove the shell for storage.