The CS Concept is making its North American debut at the 2008 New York show.

BMW's dramatic Concept CS rolled onto the stand at the hot, crowded, noisy, and chaotic Shanghai auto show, and it could only have been more refreshing if it had blown refrigerated air onto the crowd. Far racier than any BMW four-door to date, and prettier than any of the brand's current coupes, the captivating CS holds out the prospect of a tantalizing new type of BMW.

"What we have here is actually a sports car for four people," says Adrian van Hooydonk, who, as chief of design for BMW automobiles, oversaw the car's development. Carving out a space between traditional sedans and sporty coupes, the CS in theory works to the same brief as the Mercedes-Benz CLS. But whereas Mercedes refers to the four-door CLS as a coupe, everyone at BMW is emphatic about characterizing the Concept CS as a GT.

"With this car, we wanted to shy away from the idea that anything that is sporty automatically has to be labeled a coupe. That's not the case," claims Chris Bangle, head of design for the BMW Group. "Coupes are, by the nature of the word, a derivative of something. You take something and you coupe-ify it. The word means 'cut' in French. That's why, if you look back to the 1960s, a lot of the GTs were never called a coupe--they were called a GT. Because in doing them, you didn't take a big car and make it smaller."

The name CS, though, is an homage to BMW's classic series of big two-door coupes, which started with the 3200CS in 1961. (However, the first BMW to use the letters was the lesser-known, small 700CS two-door, and there also was a CS variant of the 2000.) The last of the big coupes to wear the CS designation--actually CSi--was the 1996 850CSi.

Since the last CS was an 8-series, a car that sat above the 7-series at the apex of the model range, does this show car propose a new top-of-the-line model for BMW?

Bangle at first seems to dismiss the idea: "The 7 is always going to be our absolute top-of-the-line sedan," he says. But the key part of that sentence isn't "top-of-the-line," it's "sedan." Bangle admits as much by adding: "Do we always have to think that the 7-series sedan is as far as [BMW] can go? Is there something even further?" Van Hooydonk is more direct: "In our minds, if we were to do a car like this, it would be a top-of-the-line car."

Certainly, the concept's extravagant proportions would support that status. The CS sits astride a 123.7-inch wheelbase, which surpasses that of even the long-wheelbase 7-series. It's also wider than a 7-series but much lower; in fact, it's lower than a 6-series coupe. Due to the short overhangs, its overall length falls between that of the standard and extended 7-series models.