The SLK55 AMG is the hot-rod version of Mercedes' two-seat retractable-hardtop SLK roadster, which received a thorough going-over -- including updated styling and an improved interior -- for 2009. The SLK55 AMG gets a 355 horsepower 5.4 liter V8 (link goes to photo), 7-speed automatic, upgraded suspension, steering and brakes, and a premium leather-lined interior. via cars.about.com