This heavily disguised BMW test car has triggered rumours that BMW is working on a production model of the CS concept car. The spy shots show a large sedan, like the 7-series, but with unique elements at the front-end and a generally more sportier impression.

The luxury four-seater was intended as a rival for the Maserati Quattroporte and upcoming Porsche Panamera. But last month, BMW announced that it would be focusing on smaller cars, with which the production CS, likely to be called the 8-Series, was out of the picture. However, the latest spy photos most likely show further development of the super-sedan.

Galleries: BMW CS Concept and BMW 8-series spy shots

[Source: EVO]

The Concept CS, which takes its name from highly styled BMWs of the 1960s, is longer, wider and lower than BMW’s current flagship saloon, the 7-Series. It was first shown to the public at the Shanghai Auto Show in spring this year as Asia is likely to account for a big piece of any future growth in sales of high-end luxury cars.

The CS’s most striking feature is a long, low, flowing roof, which inevitably leads to comparisons with recent ‘four-door coupes’ – notably the Mercedes-Benz CLS, Aston Martin Rapide and Porsche Panamera. But the CS is neither cut nor stretched. “It was conceived holistically as a four-door saloon,” Chris Bangle said in Shanghai. “It is not a chopped or stretched anything.” The CS’s long hood suggests a powerful engine. The face is aggressive, with a hooded, intent look to the headlights. Large air openings below the front grille seem connected to like-styled apertures for the exhaust in the rear. In between, swollen rocker panels leave the impression that the entire body rides on twin tubes.