Since its founders invented the motorcar 125 years ago, Mercedes-Benz has been tweaking and primping its vehicles ever closer to perfection. The Mercedes-Benz CL63 AMG (www.mbusa.com) may well be the culmination of those efforts. For muscle and punch, the $151,100 coupe has a twin-turbo, 536 hp, 5.5-liter V-8 (an optional 563 hp performance package is available). Yet the car rides smoothly and effortlessly, as though it knows precisely where it is going and exactly how to get there. This duality, this blend of monster movement and easy meandering, is a perfect pairing. The CL63 AMG has a silhouette that will remain contemporary a decade from now and a cabin that coddles its occupants among rich woods and aromatic leathers. Can an automobile become any better? Probably, but only if it is built by Mercedes-Benz.