Bucking the current trend, the Audi TT Roadster is available only with a cloth top. The decision to go with a cloth, rather than hard, convertible top was made because the cloth weights much less. That makes the car lighter and keeps the center of gravity down close to the road. The power-operated top can be raised or lowered at speeds of up to 30 miles per hour, according to Audi. The coupe version was unveiled in April at the New York Auto Show.