Mercedes-Benz S-Class XL testing at the Nürburgring

Mercedes classifies its models by "class," but as often as not, that comes down to one body-style. Not so the new S-Class, which is destined to push the boundaries of how many variants it can get, even without resorting to BMW-style slantbacks.

Daimler's new flagship luxury sedan is already available in two wheelbase lengths (only the longer of which will be sold Stateside), and will be offered in coupe (and convertible?) form as well. But before all's said and done, Mercedes plans on stretching the sedan even further. The largest and most opulent will be the Pullman version that will fill the void left by the departure of the Maybach brand, but slotting in between that and the existing versions will be the one depicted in this spy video.

Expected to offer an extra ten inches or so of wheelbase to the benefit of rear seat legroom, the extra-long-wheelbase S-Class will be most readily identifiable (in case there's not a standard S-Class around for comparison) by the extra side window placed aft of the rear door.

What's particularly interesting about this spy video, though, is where it's shot: the Nürburgring Nordschleife. That in and of itself tells you that Mercedes is intent on mitigating the wobble and heft associated with stretching a wheelbase that long and living up to its own vehicle-dynamics standards. See how the supersized S-Class hustles in the video below.