THE momentum which has seen Vauxhall launch three new models this year shows no sign of letting up.

Hot on the heels of its Ampera range extender, Mokka compact SUV and urban chic Adam offerings comes the new Cascada full-size convertible.

The Cascada is a four-seat, fabric-roof convertible which at nearly 4.7 metres in length is longer than an Audi A5 Convertible and positions Vauxhall in a sector that it hasn't occupied since the 1930s.

With the lines of luxury touring cars in mind, designer Mark Adams has sculpted a model Vauxhall believes will become a massive hit when it hits the streets next March.

The company, mindful of the vagaries of the British weather, has aimed to make the Cascada a practical all year round car.

So its hood, which can be opened in 17 seconds at speeds up to 30mph, will have tip-top acoustic and thermal insulation thanks to a special layer of polyester fleece between the outer and inner linings.

The car's dynamics are heightened by a rigid body that's 43 per cent stiffer than Vauxhall's last open-topped car, the discontinued Astra Twin Top, and it will also use the HiPerStrut front suspension initially used on the fiery Insignia VXR.

Also available across the Cascada range is FlexRide, Vauxhall's chassis control system which automatically adapts to suit driving style and prevailing road conditions.

And a new 1.6-litre turbocharged petrol engine producing 170PS will be the highlight of a powertrain line-up that also includes a 1.4-litre turbocharged petrol unit producing 140PS and the 2.0 CDTi 165PS diesel found in Insignia and Zafira Sports Tourer models. More powerful versions of both petrol and diesel will join the party later.

With a minimum load volume of 280 litres with the roof down, and up to 350 litres roof up, the Cascada has some practicality too, and the FlexFold rear seats electrically release and fold down for carrying longer items.

Technology is also very much to the fore with options like Adaptive Forward Lighting with up to 11 automatic lighting functions, Front Camera System including Traffic Sign Recognition, Lane Departure Warning, Following Distance Indication and Forward Collision Alert, rear-view camera, heated steering wheel, Hill Start Assist and Side Blind Spot Alert.

Vauxhall chief Duncan Aldred said: "Cascada is set to change people's perception of Vauxhall once again.

"The full-size convertible sector tends only to be occupied by very high-priced cars from premium manufacturers. With Cascada, we're offering customers high levels of equipment, technology and luxury but at an affordable price."

Full pricing will be announced when the order book opens at the start of next year.