Washington Post: “Where’s the tailpipe?” asks a middle-age man as he steps off the escalator at the Walter E. Washington Convention Center and spots the Fiat 500, a sporty, smaller car designed to appeal to the Mini Cooper set. “It’s electric?” Yes. It’s electric, just like the Chevy Volt, the Nissan Leaf and a host of other cars making an appearance this week at the annual Washington Auto Show. This year’s show is heavy on the green, with 65,000 square feet of what show organizers call the …