Sport Auto’s test driver Christian Gebhardt got his hand on a Carlsson-tuned Mercedes CLS63 AMG, and immediately went to do a zero to top speed test. In the case of the Carlsson CK63 RS that top speed is 332 km/h. That is astonishing for a luxurious, high quality, uber comfortable four-door saloon. The reason for this ferocious speed is a 625 horsepower twin-turbo V8 engine. Carlsson also tweaks the styling a bit, but that engine totally dominates everything.