Ann Arbor, we’re told, is a perfect college town -- but as it’s about 18 miles east of Chrysler’s proving grounds in Chelsea, Michigan, it’s also an ideal road trip destination for engineers exercising Fiat 500 prototypes.

We caught this duo of U.S.-spec 500 test vehicles following one white Euro-spec 500 through downtown Ann Arbor earlier this afternoon. Although we weren’t able to whip our camera out in time to catch all three Cinquecentos in a row, the U.S.-spec prototypes wore body stampings painted in black, and looked slightly wider than European models.



If our visual ruler holds true, this may lend credence to reports suggesting the 500 will grow slightly for its North American debut, allowing Fiat’s little hatchback to move to a new platform, will also underpin the Panda.

Production of the U.S.-spec cars is expected to commence in Chrysler’s Pueblo, Mexico, assembly plant this December. The base 500 will be the first to reach market in early 2011, while the 500C convertible, the performance-tuned Abarth, and a new station wagon model will follow shortly afterward. An electric-powered model and a four-door variant are also being considered.