This is our first glimpse of Citroen’s Audi-inspired styling for the new C5, in the shape of the C5 Airscape concept, due to make its debut at the Frankfurt motor show in September.Citroen’s new Mondeo competitor will follow the form of the open-top Airscape, but with a conventional three-light saloon glasshouse and four doors. The nose, with its double-chevron grille, wraparound headlights and deep lower air intake is expected to be unchanged on the production C5, apart from minor details.A radical departure for the C5 is the switch to a four-door saloon bodystyle (the old car was a hatch), also previewed on the Airscape with its neat rear overhang and flat deck-lid. There will also be a C5 estate, expected on sale in summer 2008, after a spring launch for the C5 saloon.One key element not expected on the production C5 saloon is the Airspace’s pronounced rising line along the side. Instead the C5 saloon will have more restrained, curvier metalwork.Expect the overall proportions of the production four-door to be very similar to the Airscape’s, including the long front overhang, a consequence of sharing the same platform that underpins the Peugeot 407.The Citroen’s wheelbase is, however, understood to be stretched by around 30mm over the Peugeot’s, a feature that will help Citroen’s reputation for comfort over long-distances. Indeed, expect this to be a major selling point of the C5, which is unlikely to match the Mondeo dynamically.Powering the Airscape is a mild-hybrid 2.7-litre V6 diesel with the same integrated starter motor and stop/start technology as fitted to some C2s and C3s. That’s unlikely to make production, though a mild-hybrid four-cylinder diesel is a possibility, and the C5 will be offered with a V6 diesel, unique in its class since VW dropped the layout from the current Passat.Details of the concept’s suspension remain a mystery, although information from France suggests that C5 production models might be offered with a choice of suspensions — steel springs for entry and mid-range models and hydractive gas/oil units for top-spec models.The Airscape also shows how Citroen’s design team under boss Jean-Pierre Plouie Is developing the look first introduced on the C6. The ‘planform’ around the nose — the curved bodywork around the front corner — is very different to the C6’s flat, chiselled profile.Although pictures of the interior aren’t yet released, Citroen is making big claims for the cabin’s design and quality. The steering wheel uses Citroen’s unique fixed centre-hub wheel and there is chrome trim throughout, including a section of the wheel rim.There’s no word yet from Citroen if the Airscape previews a C5 coupe or convertible, but we wouldn’t bet against it.