The CLK350 and the CLK550 are the pillars of this class, available in both coupe and convertible forms. The CLK350 is slightly more modest than the CLK550 and has a 268-hp V6 with a seven-speed touch shift automatic transmission. The CLK550 is powered by a 5.5-liter, 382-hp V8 with the same seven-speed automatic. For buyers who deem that still lacking, a CLK63 AMG cabriolet with a 6.2-liter 475-hp V8 can be ordered.For 2008, Mercedes-Benz also offers the CLK63 AMG Black Series. This coupe is essentially a production version of the CLK pace car used in the Formula 1 racing class.