This year’s Los Angeles Auto Show Design Challenge tackles a heavy question: How do you build a lightweight car that doesn’t compromise safety, styling or performance?Mercedes-Benz’s answer to that question involves a high-end rickshaw, a Smart knitted by lovable robot grandmothers and a sedan grown from seeds. For the first time in its 7-year history, the Design Challenge expanded its reach beyond Southern California and invited Mercedes-Benz design studios from Japan and Germany to participate in the annual competition. As thanks for the invite, Mercedes brought concepts that stick out amidst relatively staid designs from General Motors, Honda and Nissan like Hammer Pants at the Highland Games.This year’s rules stipulate that entries must weigh less than 1,000 pounds (1,500 with passengers). They’ll be judged by “artistic beauty, comfort, uniqueness of design, roadworthiness, sustainability, performance and user-friendliness of the vehicle.”From Mercedes-Benz Research and Development Japan’s Advanced Design Centre comes the Maybach DRS “Den-Riki-Sha” electric rickshaw. It’s more like a Rick-Segway, however, with a self-balancing electric drivetrain, albeit one that’s connected to a yet-to-be-developed intelligent transit infrastructure.The Volk at Mercedes-Benz Advanced Advanced Design Germany might have been inspired by the theme of some trendy Berlin club for their Smart 454 design. The car is made of carbon fibre literally knit by “incredibly high-tech robots that look as friendly and cuddly as our grandmothers.”Even Mercedes’ American designers offered a bizarre creation. The Biome concept is grown from two seeds that are genetically engineered to customer specifications. Cars are nurtured at Mercedes-Benz Nurseries until the two seeds grow into a seamlessly integrated interior and exterior. Even among the far-out ideas from Mercedes, this one is especially fanciful.Though they’re highly advanced designs, the compressed-air cars from Honda and Volvo, the polyhedral 3-D lattice mono-formed frame of the Cadillac Aera, the ultralight Mazda MX-0 or the combination organic-synthetic exteriors that encapsulate concepts from Nissan and Calty Design Research seem tame compared with the oddball lightweights from Mercedes.