SOME cars improve with age and Jaguar’s XK is one — at least, up to a point. It is six years since the XK8 range was introduced and its styling has matured. It still looks good in 2002.

Now it has been given a 4.2-litre V8 engine to replace its 4.0-litre and a slick six-speed automatic gearbox. For the XK8 the engine is naturally aspirated and turns out 300bhp, but in supercharged XKR form this jumps to 400bhp.

A hundred miles in the XKR Convertible (£63,350) on a brilliantly sunny early autumn morning on near-empty rural roads was a rare treat. Zero to 60 mph in 6.3sec is only part of it. The really good bits are its storming performance; its ability to overtake quickly in absolute safety; the sound of its engine; its reassuring Brembo brakes; its comfort; and its near-23mpg combined fuel consumption.

On the downside, the cockpit is not roomy enough, and what prevents the big-wheeled XKR Convertible being thoroughly impressive is its slightly flexible feel over some surfaces; it ought to do better. But the XKR was always a car to covet, and it is even more so now.