Eighteen months after its concept C study was displayed at the Geneva Motor Show, Volkswagen has unveiled the production version of its coupé cabriolet model - the Eos.Revealed to the world at the Frankfurt Motor Show, the Eos is the first four-seater car with a power-operated five-section CSC roof - that is, it has the characteristics of a hard-top coupé, sliding glass sunroof, and fully convertible metal roof.When closed, the curved roof forms part of an attractive and classic coupé body shape, yet when lowered the Eos takes on the appearance of a purpose-built convertible. It manages to look convincing in both guises because it is not derived from any other model. By not being based on an existing vehicle, the windscreen has been kept short to avoid intrusion to either headroom or entry/exit, while the rear has a compact, muscular stance. The integrated glass sliding sunroof is an innovation for this type of car, and a welcome feature in less clement weather.The Eos is 4.41 metres long, 1.79 metres wide and 1.44 metres high. These dimensions place Volkswagen's new model clearly between the Golf and Passat classes, opening up a new sub-segment in the market. The New Beetle Cabriolet meanwhile, which has recently benefited from refreshed styling, will further consolidate its position as the successor to the Golf Cabriolet in the segment below the Eos.Under the body, many major components used in the Eos are shared with other Volkswagen models, including sophisticated multi-link rear suspension, electro-mechanical power steering and an advanced range of engines. These will include four petrol engines, comprising a 1.6-litre FSI 115 PS; 2.0-litre FSI 150 PS, 2.0-litre T-FSI 200 PS; and 3.2-litre V6 with 250 PS. In addition, a 2.0-litre TDI 140 PS diesel will be available.Like the exterior, the interior has a style of its own. While many functional elements such as switches and dials are shared with other Volkswagen models, the shape of the dashboard, door mouldings and rear seats are unique to the Eos. Optional electrically activated easy-entry seats memorise the driver's and front passenger's longitudinal seating positions and - once the rear passengers have entered or exited the car - return to these at the push of a button. Also power operated is the rear latching system for the boot (as an option), which closes the final few millimetres effortlessly. The boot itself can accommodate 380 litres with the roof up, or 205 litres when it is lowered.UK prices and specification will be announced closer to the model's launch in May. However, confirmed standard equipment will include ESP (Electronic Stabilisation Programme); a pop-up roll-over protection system; front airbags (driver, passenger and side) and specially developed head-thorax airbags; 16" alloy wheels (17" for the 3.2-litre V6); air conditioning; and electric windows. Notable options will include Volkswagen's leading ten-channel, ten-speaker 600 watt Dyaudio system (as offered on the new Passat) and bi-Xenon directional headlights.