The 458 Spider is the world’s first midrear- engined car to sport a retractable hard top. In fact, the car’s entire concept of combining comfort, lightweight construction, functionality and performance, was built around that feature. The first advantage of a retractable hard top is that it significantly improves in-car comfort when closed, as it insulates occupants from both weather and noise.
The 458 Spider’s unique hard top doesn’t deform because of the pressure field that builds up at high speeds either. Cabin space and comfort are actually improved thanks to the roof’s double curvature, an element made possible by its aluminium construction but impossible to achieve with a traditional canvas soft top. The retractable hard top’s structure is incredibly light too, thanks to a simple yet ingenious mechanism. It actually weighs 40 kg less than a traditional hard top and 25 kg less than a fabric version. Its simplicity also ensures its speedy and graceful deployment as well as ensuring it is extremely compact and aerodynamically efficient. As the two sections of the roof rotate simultaneously, the 458 Spider’s hard top takes just 14 seconds to deploy or retract.
It also tucks away neatly into a 100 litre space in front of the engine bay – a huge achievement given that the roofs on most retractable hard top cars usually take up 150-200 litres. However, this incredible compactness was vital to retaining the superb aerodynamics and styling of the rear of the car and also the engine’s mid-rear position. Drop-top driving is an absolutely uniquely exhilarating experience. However, correct distribution of the airflow inside the cockpit is vital to ensuring occupants fully enjoy the top-down experience without any unpleasant turbulence. This is why Ferrari has installed an electric wind stop in the 458 Spider: once the hard top has completed folding away, the latter automatically raises to about a third of its maximum height, the optimal position established in wind tunnel testing on a 1:1 scale model. That position may, however, be adjusted by the driver both with the top up or down. It can be completely lowered so that occupants get the full benefit of the car’s soundtrack even when the car is in coupé configuration.
Design-wise, these results are the product of having moved the cut-line for the start of the roof from the waist-line to the top of the B-pillar. This simplifies the shape of the roof, making it two-dimensional with the result that it can be divided into two sections which overlap during folding.