Most Jaguar disciples considered the standard Jaguar XK coupe and roadster—with their 5-liter engines and 385 hp—naughty enough. Then came the XK-R, which added a supercharger and 125 units of horsepower. Arriving this year, the Jaguar XKR-S (www.jaguar.com) is one really bad cat. Jaguar has tuned the supercharged engine to produce a tarmac-munching 550 hp, making the XKR-S the most powerful production sports car in the company’s 62-year history. Priced at $132,000, the XKR-S displays all the bits, pieces, and aerodynamic hangings of a racecar—from vents and nostrils to a rear spoiler to optional 20-inch wheels painted a sinister black. The interior features premium leathers and aluminum or black trim.