Jaguar's dealers have had a hard time in recent years, being forced to watch the manufacturer de-value its brand and diminish their profits as it chased volume and market share.

Thankfully, the historic carmaker realised in time that exclusivity and profitability make better sense.

Exclusivity is something that customers want, particularly when choosing a supercar. So the volume game is left well behind, meaning dealers shouldn’t have a hard time finding customers, and making profit. Their real challenge will be satisfying customers' specification demands.

The standard XK convertible is a fabulous grand tourer, even qualifying as a driver’s car thanks to its lightweight aluminium body, 300bhp V8 and capable chassis. But in supercharged XKR form this car becomes a 420bhp wildcat.

During our rain-blighted test week that power would have held the car on a knife-edge of grip, were it not for the excellent dynamic stability control which lets drivers have a little fun but not get too out of shape. Although it is a large, powerful car, driving it is never stressful. It has wonderful poise, and although XKR’s suspension has been stiffened for more involved driving, comfort is maintained.

Obviously, XKR benefits from the gorgeous lines of the lesser-powered XK. Changes to the exterior are subtle but noticeable, and include bonnet louvres, a sportier grille and front bumper, aluminium-effect side vents, quad exhausts and larger alloy wheels. Inside, it gets an aluminium fascia and XKR sports seats.

Price: £76,097
Engine: 4.2 supercharged, 420bhp
Transmission: Six-speed auto
Performance: 0-62mph 5.3sec, top speed 155mph
Efficiency: 22.9mpg, 294 g/km CO2
CAP RV 3yr/30k: 47% £35,850
Rivals: BMW M6
Strengths: Great drive, looks fab
Weaknesses: Rear seat space
Opportunity: Rejuvenate the brand
Threat: Doubts over Jaguar’s future
USP: Top-down pure pleasure