Jaguar quietly trotted out its hottest XK to date, the XKR-S. Packing a 420-hp 4.2-liter V8 and sending power to the rear wheels through a six-speed automatic gearbox equipped with Jaguar’s Sequential Shift system, the XKR-S can run to 60 in 5.2 seconds and on to a top speed of 174 mph, making it the fastest Jag since the XJ220 supercar. (more…)