Like its 600LT Coupe sibling, the Spider records a significant weight saving over the model on which it is based, with McLaren's engineers achieving a reduction of 100kg over the 570S Spider. Furthermore, thanks to its lightweight but incredibly strong carbon fibre MonoCell II chassis, the convertible 600LT retains the structural rigidity of the Coupe with none of the strengthening that is usually required with conventional steel or aluminium structures.

The result is a weight penalty of only 50kg over the Coupe, which contributes to a lightest dry weight of just 1,297kg for the Spider. This is at least 80kg less than any direct competitor and the equivalent power-to-weight ratio of 457bhp per tonne underpins astonishing levels of performance and dynamic prowess.

Enhancing the Sports Series Longtail experience with open-air motoring is as easy as pushing a button to lower or raise the three-piece, powered retractable hard-top roof at speeds of up to 40km/h.

With the roof lowered, occupants benefit not only from wind in their hair, but also the memorable aural and visual drama provided by the top-exit exhausts that are unique to the 600LT. An electrically-operated, glazed wind deflector can be activated independently of the hard-top, to reduce buffeting or increase ventilation - or simply to allow more of the exhaust sound into the cabin.

Incorporating technology proven in the 650S, 675LT and 570S Spiders, the hard-top roof is more secure and wear-resistant than a fabric alternative would be, as well as offering Coupe-like cabin refinement when in the raised position. Equally importantly, it allowed McLaren's design team to maintain the focused design language and silhouette of the 600LT Coupe.

When lowered, the roof stows elegantly with the assistance of soft-close technology beneath a tonneau cover located behind the seats; with the roof raised, this tonneau storage area provides an additional 52 litres of luggage space.

The 600LT Spider benefits from the same portfolio of performance enhancements that has proved irresistible to 600LT Coupe buyers. The electronic control systems of the twin-turbocharged, 3.8-litre V8 engine have been revised, the cooling system uprated and the shorter exhausts tuned to liberate more power.

The engine produces the same 592bhp and 620Nm in the Spider as it does in the Coupe. The 600LT Spider will reach 100km/h from a standstill in 2.9 seconds, with 200km/h achieved in just 8.4 seconds - a near-indistinguishable 0.2 seconds slower than the Coupe. The maximum speed is 324km/h with the roof raised, or 315km/h with it lowered.

Performance is further enhanced by the lightweight carbon fibre bodywork that creates the Longtail silhouette and the same design of fixed rear wing as the Coupe which - despite the aerodynamic challenges posed by a convertible body - generates the same 100kg of downforce at 250km/h.

Lowering the roof of the 600LT Spider showcases the performance-orientated interior, which features lightweight Alcantara trim and Carbon Fibre Racing Seats from the McLaren P1 as standard.

The Super-Lightweight Carbon Fibre Racing Seats designed for the McLaren Senna are available as an option, either on their own or within the MSO Clubsport Pack. Further weight-saving options and measures - including deletion of the audio and climate control systems - are available to buyers determined to shave off every kilogram possible.

The new 600LT Spider is the fifth model to carry the coveted LT badge, joining the illustrious bloodline that began in 1997 with the McLaren F1 GTR 'Longtail', of which only a development prototype and nine examples were built.