Foreign cars dominate greenest vehicle list, with Honda Civic GX at the top. ...
... "Claiming the prize as the greenest model year 2007 vehicle is Honda's natural 
gas-powered Civic GX. The Toyota Prius and Honda Civic Hybrid, stalwarts on the annual Greenest Vehicles list, claim spots two and three, while the Nissan Altima Hybrid and Toyota Yaris, market newcomers for model year 2007, round out the top five. Others in the list include conventional and hybrid-electric vehicles from Honda, Hyundai, Kia, and Toyota. Domestic automakers were shut out of the top-twelve list. " ...
Via American Council for an Energy-Efficient Economy: Clean Sweep by Imports in Annual Ranking of Top Eco-Friendly Vehicles