How does it compare? There’s no BMW Z4 M (yet) and the most powerful Porsche Boxster has just 311bhp, so the SLK55 AMG is more a rival to a folding hard-top equipped M3 than anything else.

the SLK55 AMG Black Series goes 0-62 in 4.5 seconds -- 0.4 second quicker than the regular SLK 55 -- with a top speed of 173 mph. The added power comes from a modified intake, high-flow air filter ...