It might sound surprising, but all-electric vehicles are already on American roads. They just haven't quite made it to the highway yet. A growing cottage industry of Neighborhood Electric Vehicle [NEV] manufacturers is spurring the development of cars like the Zenn, which has reached a state of vehicular enlightenment so advanced it doesn't even need a tail pipe. We saw this car in May of '06, and all of us were just freaking out: 'Finally, a car!'" said Steve Mayeda, sales manager at Seattle-based MC Electric Vehicles, which sells 30 percent of Zenn's U.S. inventory, in addition to electric vehicles made by Columbia, Canadian EV, E-Ride and Miles. "Zenn was the first neighborhood electric car that actually looked and felt and drove like a real car. Everything else before that was either a converted golf cart or a car that was built from the ground up." NEVs are silent, have no tailpipe emissions (or tailpipes, for that matter) and plug into electrical outlets like vacuum cleaners. They come in two varieties: Low-Speed Electric Vehicles, which have a top speed of about 25 miles per hour and are restricted to roads where the speed limit is 35 miles per hour or less; and Medium-Speed Electric Vehicles, which reach 35 mph and are allowed on roads with a posted speed of up to 45 mph. They're exempt from federal safety regulations that mandate impact-absorbing bumpers and airbags. But to be street legal, NEVs must have three-point seat belts, windshields with wipers, headlights, brake lights, rearview mirrors and turn signals.