Some things just take a long time.

Take the Pagani Huayra Roadster: The Italian boutique automaker says it started work on the latest variant of its exotic sports car in 2010, but then scrapped it all and restarted this drop-top’s design from scratch so that the car you see here became “a project independent of its predecessor; a machine with its own soul.”

In a sense, maybe that’s not far from the truth. While the Roadster uses the same Mercedes-AMG-built turbocharged V12 as the Huayra coupe, a 6.0-litre unit good for 764 hp, Pagani accomplished the impressive feat of making the Roadster lighter than its hardtop sibling (by 80 kg, for a 1,280-kg curb weight) while also increasing the chassis’ torsional stiffness.

The key to a convertible is its roof, and the Huayra Roadster will be offered with two different options: one is a carbon-based top with a glass insert that maintains the Coupe’s appearance in profile; and the other a fabric-and-carbon piece that can be stowed in the car and easily installed (in a few simple steps, says Pagani) in case of weather emergency.

Lightweighting is a big deal for this company, apparently, which has stuck with a seven-speed automated manual transmission with a single clutch, which Pagani says is 40 percent lighter than a comparable dual-clutch setup.

Normally, chopping the top off a coupe results in a less-rigid car, but Pagani’s ace-up-its-sleeve is the company’s history as a specialist in carbon fibre, a lightweight material known for its strength. The Huayra Roadster benefited from two of Pagani’s latest inventions, Carbo-Titanium and Carbo-Triax HP52, which it says are more advanced than what goes into Formula 1 racecars.

The Roadster also benefits from Pagani’s latest suspension design, with parts forged from a lightweight aluminum alloy called Hi-Forg, designed specially for this car, which Pagani says resulted in suspension pieces 25 percent lighter than in the Huayra coupe.

That suspension also works in concert with an active aerodynamics system comprising two flaps each, front and rear, that adjusts to keep the bottom of the car parallel with the road at all times for optimum airflow around the body.

Italian tire manufacturer Pirelli stepped up to create a special rubber compound for the Roadster’s tires, which Pagani boasts help the car achieve 1.8g of lateral force in skidpad testing. Somehow, incredibly, these sticky tires were also designed for low rolling resistance to help reduce fuel consumption and CO2 emissions.

The Huayra Roadster will retail for roughly $2.4 million, but unfortunately for buyers just finding out about it now, all 100 units to be built have already been spoken for.