Mercedes-Benz claims to have a vision of the car market 50 years from now, and their contribution is called the SilverFlow (but ironically looks like gold). Instead of being constructed from metal, plastic and fiberglass components, the SilverFlow is made of micro-metallic particles that are controlled by magnetic fields. A key fob stores different designs and components allowing the driver to restructure the car at will as changes only require magnetic adjustments. But the best part? The car will have the ability to self-repair. You, of course, will stay dead. But your kids will really appreciate that the car went unharmed. Hit the link for a full gallery. [jalopnik]
The wheels can be held together with properly hidden braces and drive components on the rim of the wheels beneath the fender cowls. Of course, being a mockup it would look a lot more elegant in concept than it would in real life, and it would probably be more efficient a design to simply have a center hub with spokes than having a hula-hoop with a circular track to keep spokeless wheels in place.