Wizard of Oz on Buick road

 The four-door Invicta sedan is the work of former GM-Holden designer and Monash University graduate Justin Thompson, who says the sweepspear from the classic Buick is a significant part of the car. The sweepspear is the curved line along the car's flanks, which dips at the rear door.

“We really had only one chance to get it right,” he says. “The designers were given five weeks to go from concept to reality.”

Thompson spent seven years at GM-Holden before joining the overseas GM Empire.

GM-Holden's expertise has been recognised by the parent company before, in the Denali XT concept four-door ute unveiled early at the Chicago Motor Show in February.

The Denali was the work of the Holden design team in Melbourne. The significance of the Invicta's unveiling at last month's Beijing Motor Show was not lost on GM executives. Buick is GM's biggest passenger brand in the communist country. Last year it sold 332,115 cars in China, which was significantly more than the 185,792 Buicks sold in the US.

The Invicta (Latin for invincible) is the face of Buick's new global design and an evolution of the Riviera concept car.

It is powered by a direct-injection turbocharged four-cylinder engine mated to a six-speed automatic transmission.

The engine delivers 186kW/298Nm, which is performance that is normally associated with a high-end six-cylinder. The car was jointly developed by GM design centres in North America and China to meet customers' expectations in the world's two largest car markets.

Using virtual-reality centres in Shanghai and Warren, Michigan, designers fused the best ideas drawn from both cultures.

GM vice-president of global design Ed Welburn says the car sets a new design standard for Buick.

“It couldn't have been achieved by one studio working in isolation,” he says.