| Sneak preview | 2008 Goodwood Festival of Speed | 2009 Jaguar XF-R |

A black cat crossed the path of thousands of spectators at the Goodwood Festival of Speed this weekend. The barely-disguised Jaguar XF-R was driven up the hill by Jaguar's Head of Vehicle Development, Mike Cross, the crowd thrilled by his exuberant sideways driving. Although wearing disguising matt black paintwork some of the bodywork revisions are still clear. The front features a far deeper front bumper punctured by numerous air intakes for the engine. The powerplant is suspected to be a 5.0-litre supercharged V8 unit with around 500bhp.

Whatever is under the vented bonnet it certainly makes an appealing sound, the quad tailpipes providing a rousing note above the protesting tyres on the run up the Goodwood hillclimb course. Given how much the inside, unloaded wheel was spinning and smoking it seems unlikely that Jaguar has fitted a limited-slip differential to its new XF performance flagship. Instead, its prodigious grunt will be kept in check with electronic traction and stability controls. However, as Cross ably demonstrated, it's likely that it will be possible to switch these off.

The big cat's suspension and brakes have also been uprated for the high performance R model. Bigger discs with multi-piston callipers will help stop it quicker and be more resistant to fade. The XF-R rides on massive 20-inch wheels and gains a wider track for high-speed stability and agility. The six-speed automatic will offer a Sport function, speeding up the gearshifts whether selected via the wheel-mounted paddles-shifters or left to swap ratios automatically. It's likely selecting the faster shifts will also change the throttle mapping, for quicker responses.

The new XF-R is rumoured to be officially unveiled at the British Motor Show next week and in showrooms early next year. When it arrives the XF-R should prove to be a serious rival to BMW's M5, Audi's RS6 and the Mercedes AMG E 63.

Kyle Fortune - 14 Jul 2008