The development of the model Infiniti hopes will crack Europe’s premium compact saloon market — dominated by the BMW 3-series — has shifted to the Nürburgring.

Prototype versions of the new Infiniti G-series, set to be revealed in production form at the Detroit motor show in January, are now out in the open for the first time, revealing a model with a slightly larger footprint than the current four-door saloon.

The heavy disguise hides the styling intricacies, but new Infiniti boss John de Nysschen confirmed at the recent Paris motor show that the acclaimed Emerg_e sports car concept would heavily influence the look inside and out of the new G-series.

And Infiniti's design chief Shiro Nakamura told Autocar earlier this year that the new G-series would be "much sportier and more dynamic than the current car".

Crucially, and unlike the current car, the new G-series will be sold with four-cylinder petrol and diesel engines. The Mercedes-supplied units will be offered straight from launch in mid-2013.

Infiniti insiders have also revealed that the dynamics of the new G-series will be much more suited to European tastes than the current car, hence the extensive development at the Nürburgring. Coupé and convertible models will also be part of the line-up, as rivals to the upcoming BMW 4-series range.