Porsche 911 purists scoffed at the Cayenne when initial production began in 2002, but the five-passenger SUV quickly became the German automaker’s best-selling model. Now Porsche is hoping for a similar market demand for its all-new four-door: the Porsche Panamera. The sports sedan, which derives its name from the Mexican road race La Carrera Panamericana, features an optional adaptive air suspension system, a 7-speed double-clutch transmission, and a direct-fuel-injection V-8 in each of three model variants: the rear-wheel-drive Panamera S, all-wheel-drive 4S, and turbocharged Panamera Turbo. The Turbo’s engine delivers 500 hp to all four wheels and reaches 60 mph in just 4.5 seconds. This is not your typical Sunday-cruise saloon. This is a bona fide Porsche. Pros: A sports car masquerading as a four-door sedan. Cons: Love-it or hate-it exterior design.