Though the Mercedes-AMG GT S bears more than a passing resemblance to the Porsche 911, this elegantly proportioned two-seater makes an entirely original statement with its innovative engineering and striking styling. The GT S’s all-new 503 hp, 4-liter twin-turbocharged V-8 is the world’s first power plant to combine so-called deep-V turbochargers (which reduce lag and are nestled between the two cylinder heads) with dry-sump lubrication (which ensures proper oil circulation during h…