Vauxhall and Opel are to produce a new large car which General Motors' European engineers believe will offer a radical alternative to Mercedes' E-class and BMW's 5 Series.

The new model, likely to come to market in 2004, is described by senior Opel designers as "surprisingly different, a new way, not just another big car".

Sharing components with Saab, Cadillac and Fiat, the new Vauxhall/Opel will be larger than the Omega and incorporate a flexible format interior.

Hans Seer, Opel design director, claimed Volkswagen's large D1 saloon was "conservative by our standards" and he revealed that the car's "interior parameters" had already been laid out.

Mr Seer acknowledged that GM's European brands could not attack BMW and Mercedes in their own territory.

"But we can attack them with totally different answers," he said. "Zafira's flex-seven cabin format was not just a one-shot affair. We are designing the larger car from the inside out again."

Opel executives were speaking at the unveiling of the new Vectra in Frankfurt. They confirmed the Signum "crossover" MPV/saloon would go on sale in spring 2003.

Mr Seer said Opel benchmarked the Vectra, which cost £610m to develop, against the Ford Mondeo for ride and handling and the Audi A4 and VW Passat for interior quality and space. (November 22, 2001)