Deliveries of the McLaren MP4-12C Spider will begin in November. The retractable hard top, top left, adds just 40kg over the fixed roof version.

MCLAREN Automotive has announced that it has cut the roof off the MP4-12C with the unveiling of the new 12C Spider.

It features a unique RHT folding roof system that may be operated while on the move, and the same carbon "MonoCell" chassis as its hard topped sibling. First deliveries to customers are planned for November this year.

McLaren Automotive MD Antony Sheriff said: "I am really excited to announce that the new 12C Spider is now available to order at new McLaren retailers worldwide. The launch of our second model is an exciting milestone in the growth of our company.

"While the 12C is the technological essence of a race car, the 12C Spider incorporates an additional dimension. 12C Spider owners will love the opportunity to lower the roof and hear the unhindered howl of a V8 twin turbo engine at full throttle. It undoubtedly enhances an already euphoric 12C driving experience.

"The 12C Spider delivers all the thrills characteristic of a high performance roadster, and yet transforms into a raucous track beast at the flick of a switch. I can't wait to see it on road and track with customers later this year."

The 12C Spider's power from its bespoke 3.8l V8 twin turbo engine is transmitted to the car's rear driven wheels through a 7-speed SSG dual-clutch transmission, which itself provides lightning-fast gear changes through rocker-mounted shift paddles affixed to the rear of the steering wheel. A clear view of the 12C Spider's lightweight M838T power plant is available through a glass screen positioned behind the tonneau cover.

In terms of the figures, opting for the Spider version will see you hit an identical 0-100km/h time as the hard top derivative at 3.1 seconds, but you will have to suffer the loss of two tenths of a second to 200km/h and unfortunately as the owner of a private air strip or a government issued drive-as-fast-as-you-like permit for that road near Upington, you will only be able to do 329km/h instead of 333km/h.

McLaren has a very strong reputation in the world of carbon fibre and it was natural for its engineers to apply this expertise when developing the groundbreaking one-piece moulded chassis of the 12C. With the 12C designed originally as a convertible, its 75kg "MonoCell" requires no additional strengthening for it to feature in the 12C Spider. The result is a sports car almost identical to its fixed roof equivalent in performance terms, and weighing only 40kg more with the addition of a convertible roof system.

The retractable hard top of the 12C Spider is operated using a switch in the lower section of the centre console inside the cabin, taking less than 17 seconds to raise or lower. Unlike many other convertible models, the roof can be operated while the 12C Spider is moving at speeds of up to 30km/h.

Behind driver and passenger sits a rear windscreen which may also be electronically lowered and raised. With the roof lowered this acts as a wind deflector to minimise disturbance to the occupants. With the roof raised the rear window can be lowered, allowing the exhilarating noise of the engine to flood the cabin on demand at any time.

With the roof raised the area under the tonneau can be used as an additional luggage area which provides 52l of storage space. Bespoke luggage has been designed specifically to fit this space and is supplied as standard with every 12C Spider.

The 12C Spider also features a passive Roll Over Protection System to maximise occupant safety. Each buttress contains a steel structure designed to absorb impact energy and protect both driver and passenger.

Vehicle lift will be available as an option on the 2013 model. The system allows the 12C Spider to be raised front and rear for improved ground clearance.