Spy photographers have recently caught Mercedes-Benz engineers testing a prototype of the upcoming C63 AMG Black Series sedan in Northern Sweden. The pictures clearly show the prototype with some temporary fenders and a different hood that distinguishes it from the standard model (new bodywork will replace the fenders for production). Also to be included on the car will be a new front spoiler, a new rear diffuser, and a redesigned hood.

Power will most likely come from a new 5.5-liter twin-turbo V8 with around 517 hp. Other reports are stating this engine could turn out to be a naturally aspirated 6.2-liter V8 with nearly 510 hp. Regardless of which engine, it will be more powerful than the current BMW M3 Coupe and Audi RS5. A sedan version will be launched first, followed shortly after with the coupe. Photos courtesy of gmotors.co.uk.