This pre-production test car's camouflage obscures the headlights, taillights, bumpers and some sheetmetal details, but the extra length of the rear doors and the double-thickness B-pillar are harder to hide.
According to our spy photographer, the Pullman packs around eight inches of extra length over the 'regular' long wheelbase S-Class.
But that pales in comparison to the Pullman variants of previous generations of S-Class, which were essentially bespoke stretch limousines.
The new S-Class is expected to make its debut in May, with the full range eventually encompassing five distinct body styles.
The first models to launch will be the regular wheelbase sedan and a long wheel-base sedan, followed by the S-Class Coupe - which will replace the CL - and a four-door convertible. The Pullman will join the range sometime in mid-2014.
The S-Class Pullman will likely make use of Benz's range of turbocharged V8 and V12 engines, with a V6 hybrid also a possibility.
With its substantial rear cabin space and emphasis on luxury and comfort, the S-Class Pullman is also expected to be popular in the Chinese market, where most wealthy businessmen prefer to hand driving duties over to their chauffeur.