(Wed 17 Feb 10)

The most dramatic car on Jaguar's stand at the Geneva Show (unless there's something else they haven't told us about yet) will be an XKR Coupé fitted with a new optional pack.

It's called the Speed And Black Pack, it costs £4000 and it makes this the fastest production XK ever. That is a more simple process than it sounds, because all Jaguar has done is to raise the electronically-limited maximum speed from 155mph to 174mph. No modifications to the 503bhp supercharged engine were required, but to help maintain stability at the greater possible speeds Jaguar has fitted a revised front splitter and larger rear spoiler, while also reducing the sensitivity of the steering as you whisk along the autobahn.

All of this is available in the £3500 Speed Pack, which also includes body-coloured side sills and rear diffuser, red brake calipers and various pieces of exterior chrome detailing. The extra £500 required for the full Speed And Black Pack gets you gloss black alloy wheels, window surrounds and front grilles and body-coloured front and rear spoilers and bootlid finisher.

The Speed Pack is available for cars painted in Ultimate Black, Polaris White, Salsa Red, Liquid Silver, Lunar Grey, Kyanite Blue and Spectrum Blue. Speed And Black Pack models have to be in one of the first three colours, and there is no such thing as a Black Pack.

In other XK news, a tyre repair kit has now replaced the spare wheel in all 2011 model-year cars. The wheel well is now carpeted and can hold a specially designed accessory suitcase, though frankly we'd rather have the spare wheel back.

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