McLaren says its MP4 12C Spider, officially launched today at the company's headquarters in Woking, has exactly the same carbon-fibre monocell chassis as its fixed-roof sister.

According to managing director Antony Sheriff the 12C was designed as a convertible from the start, so there's no sacrifice in terms of torsional rigidity or performance, while the simple, two-piece retractable hard top adds only 40kg to the weight of the car.

“While the 12C is the technological essence of a race car,” he said, “the Spider incorporates an additional dimension.”

“12C Spider drivers will love the opportunity to lower the roof and hear the unhindered howl of a twin-turbo V8 at full throttle.

“The Spider delivers all the thrills of a high-performance roadster, and then transforms into a raucous track beast at the flick of a switch!”

460KW AT 7500RPM, 600NM FROM 3000-7000

Mechanically identical to the coupé, the Spider accelerates from 0-100km/h in the same 3.1 seconds, is only a tenth of a second slower to 160km/h (6.1 versus six seconds flat) and tops out at 329km/h compared to 333 for the hard-top.

Quoted fuel consumption (11.7 litres per 100km) and CO2 emissions (279g/km) are the same for both models

The Spider's retractable hard top is controlled by a switch on the centre console; it takes less than 17 seconds to raise or lower and can be operated on the move at up to 30km/h.

There's also a rear windscreen that can be electrically raised behind the seats to minimise buffeting with the roof down - or with the roof up, you can lower the screen so that there is no partition between the engine bay and the cabin, and really get the full benefit of that twin-turbo V8 howl.

With the roof up, you can also use the 52 litres of space under the tonneau as extra storage. Each spider actually comes with specially made luggage, designed to fit that space - just remember not to lower the roof while it’s in there!

Finally, the streamlined buttress behind each seat hides a steel roll-over bar.

NEW COLOURS AND TRIM

The Spider and the updated 2013-spec coupé will be available in two new metallic finishes - Volcano Red and Volcano Yellow - in addition to the 15 standard colours.

Inside, a new interior trim allows customers to select high quality semi-aniline perforated leather and alcantara synthetic suede in a variety of combinations to suit their personal taste.

A new alloy rim design - as well as an optional 'diamond cut' finish on existing designs in either silver or grey - has been added to the list of options, as has a vehicle lift system that raises the suspension by up to 40mm at the front and 25mm at the rear, and holds it there to clear driveways and speedbumps, up to 60km/h.

The new 12C Spider will be priced from £195 500 (R2.5 million) in the UK and is now available to order from McLaren's 38 dealerships in 22 countries, with deliveries to first customers planned for November 2012.