The SLK 55 AMG is a high-performance variant of the successful SLK-Class roadster from Mercedes-Benz. As with all AMG models, the SLK 55 sports wider fenders, a lower stance, quad tailpipes, enlarged air intakes, and, of course, a more powerful engine.

The SLK 55 was first introduced in 2005 and was updated for the 2009 model year and beyond. The car's 5.5L V8 is unchanged with an output of 355 horsepower at 5750 rpm and 376 pound-feet of torque at 4000 rpm.

The rear-wheel-drive roadster sprints to 62 mph in 4.9 seconds or less. Power is transferred by the AMG Speedshift 7G-Tronic transmission with steering wheel gearshift paddles. Updated for 2009, gearchanges in the "S" (Sport) and "M" (Manual) driving modes are around ten percent faster than before.

Redesigned 18-inch AMG wheels feature a multi-spoke design and titanium grey finish. New, high-sheen 18-inch AMG light-alloy wheels in a twin-spoke design are also available. The front brakes have perforated discs measuring 345 x 30 mm. The rear discs measure 300 x 22 mm.

The 55's steering has also been updated. The all-new direct steering system with variable servo assistance newly designed steering rack. This allows a ratio spread from 15.8:1 to 11.5:1, allowing the driver to experience more responsiveness at around five degrees or more from the centred position.

While lesser SLK models sport an F1-style front fascia, the SLK 55 AMG forgoes that styling treatment. Instead, the AMG model wears a wider lower grille, a blacked-out lower lip, front-mounted air vents and smoked headlights.

The rear fascia of the SLK AMG is similar to the standard SLK, but features smoked taillights, a unique bumper and a quad-exhaust system.