All three Torinese design houses are showing concepts at Geneva this year, a big difference to last year's situation. Pininfarina's offering is the Duettottanta: a name that evokes the legendary 105-series Duetto, but also the years of activity at Pininfarina, which launches the celebrations for its 80th anniversary with this concept car.  

The Duettottanta is a classic interpretation of the two-seat roadster format, with very understated and elegant lines. "We wanted to connect to the Duetto spirit without resorting to obvious retro cues," said design director Lowie Vermeersch. "It should appear to be light, to fly through the air... not be rooted to the ground."

Taking us around the car, Vermeersch goes on to explain how the rear end pushes up, not down, with the design formed around two key lines: the crisp shoulder line that encircles the car and a complimentary sharp fender crown line that runs from the headlamps and along the beltline before lightly dropping down into the rear corner of the car. The intersection of the two lines at the rear forms that subtle cuttlefish shape that echoes the original Duetto.

There's a strong shadow beneath the shoulder line and what appears to be a shallow concave section in the door but closer inspection reveals more subtlety to this area. "It includes a rising negative core line, which allows us to control the light more precisely than a big hollow," explains Vermeersch. Slim LED headlamps and tail lamps are hung beneath this core line and the composition is completed with a bold three-dimensional interpretation of the Alfa shield that appears to be thrusting outward from the engine bay.

The interior is trimmed in black and white leathers, with the white upper IP appearing as a continuation of the hood volume, dropping down through the door linings. The pair of large dials and associated three minor dials also hints at the 105-series, as does the deeply-dished steering wheel, but the rendition is thoroughly modern, with piano black finishes and with the binnacle floating above the IP.

We always get worried when we hear the F-moniker on a Mercedes concept: uh-oh, they're the wacky ones devised by engineering – more a piece of eccentrically-wrapped technology rather than a svelte showcar. But not this time. The F800 Style fulfils three roles: firstly, the styling previews the new CLS, due later this year, particularly the front face, grille and headlamp treatment. More importantly, it outlines a proposal for an elegant sister model to the CLS, a new compact four-door coupé of 4.7m, sitting on a long 2924mm wheelbase with a generous interior package. Lastly, the F800 Style showcases a modular rear-drive platform that could take either plug-in hybrid or else fuel-cell electric drivetrains – a not-unrealistic future scenario for automakers.

Seen on the first day of the show, the styling feels a little overwrought, with a lot of overlaying elements worked into one car. This is particularly true of the front end, which will be interesting, as, according to head of design Gorden Wagener, all future models will get this brand face, with the main grille surround pulled out from the surrounding surfaces, a bold horizontal grille bar in body color topped with chrome and the dominant Mercedes star in the center, plus an extra u-shaped grille woven in below.

The wheels are notable for offering a new take on a finned design. The five broad spokes are finished in matte black with a series of delicate fins woven in that direct air through the wheel. Inside the car, the theme is one of lightness and fine wood surfaces. Large areas are covered in a new look bleached driftwood-finish veneer that covers the center console, door armrests, seat backs, seat bases and steering wheel. Seat frames are in magnesium with a carbon fiber laminate across which resistant netting is stretched, giving a semi-transparent appearance. Finally, the steering wheel design provides another advanced link to justify the F-moniker: the lower part appears as an aircraft-type controller and the upper part as a conventional rim.

The Flextreme GT/E is Opel's way of showing that the oily and electrical bits under the Ampera can work in other sectors too. As an extended range electric vehicle (E-REV) it is, according to design director Mark Adams, proof that "electric cars can be sexy, exciting and aspirational".

It's a long, low car, with its proportions exaggerated by the long arch of the roofline that ends at the very rear of the vehicle. Adams and his team have sought to reduce the aerodynamic drag as much as possible to maximize the potential of the drivetrain, and the result is a Cd of just 0.22.

The familiar Opel/Vauxhall grille is stretched into a broad mouth mounted very low, the extended nose section helping to circumnavigate ped-pro legislation and avoid a high-set frontage. The wing graphic that debuted with the Insignia features heavily in the front lamps – not just in the shape of the surround but also in the design of the lamp itself. This motif then continues to form the raised section of the hood.

The elongated profile features the Opel/Vauxhall ‘blade' shape – although given a slightly different interpretation here – before wrapping around to a curvaceous tail, with echoes of Insignia in the flip-up angle of the deck lid. Pronounced rear wheelarches, partly separated from the main body of the car, give something of the look of a Porsche 911 Turbo when the car is viewed from the rear. They also house aerodynamic devices that extend backwards at speed, squaring off the rear of the car and reducing the drag.

Adams points out that the team wanted to create something that wasn't easy to pigeon hole, and to that end they've succeeded as the Flextreme GT/E has aspects of sports car, shooting brake and sports saloon in its design. If this is a hint of the car maker's future design direction, then that future looks promising.