Cross a motorcycle with a small car, and you get a new kind of hybrid -- the three-wheeler Auto makers -- even some big ones, like Daimler-Chrysler's (DCX ) Mercedes-Benz -- have been developing car-motorcycle hybrids and other three-wheeled vehicles for years. But what's different now is that some of these concepts, such as the Volkswagen GX3 unveiled this month at the Los Angeles Auto Show, could actually make it to the marketplace (see BW Online, 1/12/06, "Concept Cars Are Getting Real"). And the GX3, backed by VW's global distribution capability, would stand a chance to develop a niche market....