Jaguar calls this the ultimate XK. Looking at the performance figures, it's hard to disagree with that assessment.
The XKR-S has a restricted top speed of 174mph (19mph more than the XKR) thanks to a tweaked version of the current 4.2-litre supercharged V8 that has 420bhp and 413lb ft of pulling power. The XKR-S can travel from standstill to 60mph in 4.9 seconds.
Its six-speed semi-automatic gearbox is operated using paddles mounted on the steering wheel. The car also features revised suspension, with bespoke springs, dampers and an anti-roll bar to improve ride and handling. The brake system is, says Jaguar, the most powerful available on any of its cars.
Visually, it's distinguished from the XKR by subtle body upgrades that include new front and rear bumpers, rear spoiler, 20-inch alloy wheels and a range of discreet interior revisions.
The XKR-S is expected to go on sale this summer for about 85,000. But if you want one of the 200 being built, you will have to move just as fast as the car itself.