The 2012 Tesla Model S is set to go on sale by the middle of next year, but there has been only a smattering of pricing and production news about the electric sedan since we got our first look at the car two years ago. Then, out of the blue, a reader snagged these shots of a Model S mule whirring about in Ann Arbor, Michigan. The prototype wore no camouflage—although its loose-fitting body panels made it look as though it had spent some time in a rock tumbler—so we were able to make out a few subtle differences between the production Model S and the cars Tesla has been showing off for a while. Funk Flex Find Flex On Google+