JAGUAR has lifted the lid on the most powerful and fastest open-topped model the company has ever built.

The new XKR-S Convertible makes its debut at the upcoming Los Angeles Motor Show and will cost from £103,000 when it hits the UK early next year.

Using the same 5.0-litre supercharged V8 petrol engine as its coupe stablemate, the convertible's performance is savage.

Driving the rear wheels through a six-speed automatic gearbox with Active Differential it can blast from zero to 60mph in a fleeting 4.2 seconds and on to a top speed of 186mph.

It also completes the big cat's XK range, with both hard and soft-top derivatives of XK, XKR and XKR-S in the line-up.

The use of lightweight aluminium gives the XKR-S a high torsional rigidity making it the stiffest car in its class and a Performance Active exhaust makes for a snarling soundtrack.

Underpinning the car's performance is a package of suspension upgrades to refine the XK's dynamic abilities, plus lightweight  forged 20-inch alloy wheels and recalibrated steering settings.

Visually, the XKR-S Convertible has a new bumper design with a wider, lower air intake plus carbon fibre splitter while vertical panels channel air down the side of the car along new sills, which emphasise the 10mm reduction in ride height.

And the interior boasts Jaguar Performance seats with increased support for driver and passenger during high-speed cornering.

The seats are also finished in carbon leather and feature 16-way adjustment and heating while carbon is also used to trim the cabin.

Jaguar says the acoustically treated hood will open and stow in 18 seconds and has been proven at the car's maximum speed.

Black is its standard colour, though there are a further six optional shades available, and the car itself also comes in six colours, including Polaris White and British Racing Green, a tribute to Jaguar's competition heritage.

Design director Ian Callum said: "Taking the track-oriented ethos of the XKR-S Coupe and applying it to a convertible is very exciting.

"There is a real spirit and thrill to driving with the roof down and in a car capable of these speeds that is going to be exaggerated to create a very dramatic and special experience."