It surprised many to see this concept on the Seat stand. A white exterior model only, it was missed by many designers at the show - its limelight stolen by the VW stand next door and Audi's A1. The overall impression did little to counter a suspicion that Seat is sometimes the VW group's forgotten marque, and that its positioning in the overall brand hierarchy is somewhat unclear.

However, the design is not to be dismissed, because on closer inspection the IBE is well resolved, and previews design boss Luc Donckerwolke's new language for the Spanish brand. Essentially a B-sector hatch, it is shorter, wider and lower than the Ibiza, endowing it with a strong set of proportions - the wheel at each corner, gently flared wheelarches and sharply defined rear shoulder giving the car a strong stance and planted feel.

The overall surface treatment is quite simple, but extremely well resolved. Note the flanks of the car, which seem to 'clasp' the inner body the section - the cant rail and A-pillar (which both sit slightly proud of the roof and windscreen) continuing into a sharp ‘rib' over the top of the fender. This line terminates at the inner corner of the upper headlamp 'finger', which are similar in shape to the LED strips Audi is currently using in its headlamp units - but here set into the body surface - and repeated again at the rear of the car.

A lower light catcher successfully takes excessive mass out of the flank, while the discontinuous shoulder line (a theme on many cars in Geneva) works well, creating a visual link with the Ibiza, and defining a particularly strong rear shoulder surface, which flows elegantly around to the upper surface of the trunk. Designed to show Seat's (and the wider VW group's) electric drivetrain technology, it was also pleasing to see the Spanish brand eschew the trend for overt use of green highlights and graphics, instead using a printed circuit board motif in the lower grille, which is subtly echoed by the grooves in the brake discs to denote the powertrain.

Turin-based IDEA Institute presented its Sofia showcar at the Geneva show, showcasing a new design direction for a hybrid-powered four-seat sedan. Shown as an exterior only model, the Sofia is a streamlined study with a sculptured hood, fenders that rise above the beltline and a dynamic shoulder leading to a pronounced rear diffuser.

At the front, a gaping grille leads to slender twin LED strips to give the car a strong, immediately identifiable DRG, slightly reminiscent to that of a current Aston Martin. The outer concave areas of the hood lead off below the A-pillar to become the shoulderline of the car, which continues to widen until it reaches the C-pillar, where it rises to disappear into the DLO. It is this intersection that appears particularly contrived, as the shoulder becomes convex and seemingly pinched beneath the C-pillar. It does however give definition to the rear haunch.

Otherwise, the model seems fairly sedate for a concept car, though it does feature interesting details such as the wraparound panel concealing an air inlet aft of the front wheelarch and a boneline that rises between the doors to underscore the DLO. This element is carried over from the top of the front fender and disappears into the side window surround. Upon closer inspection, the lightlines on the vehicle are not dissimilar to the six passenger Tesla Model S, and the Sofia is also nearly identical in its proportions.

At the rear, the visual mass of the high deck has been reduced through the implementation of a large rear diffuser and plastic expanse above. This lends a layered appearance, with the contrasting red body seemingly floating above, and elegant LED taillamps nestled into the far corners beneath recesses.

The Sofia is a large vehicle - measuring 5097mm long, 2006mm wide and 1381mm tall - that seemingly contradicts its environmental credentials in its demeanor, with an aesthetic more suitable to a sports car than a sedan. But as the Fisker Karma and aforementioned Model S have proved, perhaps this is the aesthetic required for the alternatively propelled vehicles of the near future.

The sixth member of the third generation Renault Megane family - the Coupe Cabriolet - was unveiled at Geneva 2010 and completes the range. It's only the second Megane hardtop CC though, as the first-generation model only offered a cloth-top convertible.

The designers behind the new CC have kept the previous generation's innovative glass folding roof but softened all the exterior lines - which is a good thing. The older CC, lacking the unusually 'stepped' rear visual interest of its 'ass shaking' hatch sibling, was very boxy, due in part to the constraints that folding hardtops can often dictate around the back of the car.

Conversely, while the old Megane CC lacked a little of its hatch's coherent design, the new CC is an improvement on the somewhat dull third-generation hatchback. The new CC shares its hatchback's shallow scooped hood, but beyond the A-pillar things change quite a bit. The soft feature line that starts by curving around the fender is more shapely than on the hatch, as it dips under a much lower side mirror - mounted on the body of the car rather than within the quarter-light area behind the A-pillar. As this soft line extends rearward it creates a subtle but wide and gently sloping shoulder that adds to the car's solid but graceful feel. New rear lights situated on each corner feature twin linear shaped LED brake lights to add some distinction.

Inside, the dashboard is stock Megane but the interior door panel trim is bespoke to the CC, featuring a butterfly wing shape. To reduce buffeting from the wind with the top down, a centrally located fixed glass wind deflector has been added behind the rear seats too.

There is no shortage of C-segment compact coupe cabriolets available in 2010 - from the Pininfarina-assembled Focus to Peugeot's 308 CC and VW's Eos - but this Megane CC compares well again in design terms within their company. It goes on sale mid-summer.