Smart Roadster Coupe Brabus V6 Bi-Turbo, 2003. A prototype version of the Roadster Coupé with two merged 3-cylinder engines to celebrate the 100th anniversary of the Solituderennen. The car had the same power-to-weight ratio as a Porsche 911 Carrera 4S. Ten cars were built and presented at the Castle Solitude. They are not available for sale and are not even allowed to be driven on public roads in Germany