University of Michigan students unveiled their new design for a worldwide solar car competition Wednesday, with an odd shape dictated by changes in the rules. The car, dubbed Generation, will compete in the World Solar Challenge, an 1,800-mile, weeklong endurance contest across the continent of Australia from Darwin to Adelaide that takes place every other fall. \"We spent a lot of time refining the design [for the changes] and we\'re feeling really good about it,\" said Eric Hausman, a U-M senior studying industrial and operations engineering who is the team project manager. The most significant rule change for 2013 is that cars must have four wheels instead of three, the biggest shift since 2007 when the drivers moved from prone to sitting upright, he said. Both requirements had led to teams come up with new shapes for the vehicles that run off a battery charged by sunlight. \"So in \'07, you had to figure out where to put the driver in the air foil,\" Hausman said. \"This year, it\'s similar. You have to figure out how to arrange the wheels and the driver in the new optimal position, and we think we\'ve found that basic geometry.\" That basic geometry was asymmetrical, he said. \"We have the driver and two wheels all in one giant fairing (aerodynamic cover) on the left side of the car and on the right side, we have two small fairings -- one for each wheel,\" Hausman said. \"Aerodynamically, it\'s about creating as few bumps on the surface as possible. The design also reduces shading of the solar cells by placing the canopy to the side.\"