STOCKACH, Germany — Kicherer, the Mercedes tuning house, has gotten its hands on the top-of-the-line Mercedes CL600 coupe. After dropping one zero from the name, Kicherer has added an invigorating engine and exterior treatment to create the CL60.Although the stock 517 horsepower twin-turbocharged V12 already holds its own, the German tuner upped power an extra 53 horses to bring total output to 570 hp and 664 pound-feet of torque. Other performance mods include a 1.0-inch-lower suspension, modified transmission control module and locking rear differential that help get power to the wheels efficiently while keeping the ride comfortable.Exterior changes include a full body kit with new front and rear lips, side skirts and rear diffuser. A four-tailpipe sport exhaust system and 20-inch Kicherer RS-1 wheels help to complete the treatment.Inside Line says: Kicherer manages to make Mercedes' high-end coupe even hotter. — Mike Lysaght, Correspondent