The new Smart Roadster will joust with Ford's StreetKa, while the Smart Roadster-Coupe will square off against the SportKa. Both Smart variants are built on a slightly longer version of the current Smart city car. They have removable plastic panels fastened to a steel space frame plus a two-piece removable plastic hard top that stows in the trunk. Power comes from an 80-horsepower turbocharged 700-cc three-cylinder engine that is mounted in the rear. Global Auto Net