The all-new E-Class was just revealed last month at the Detroit Auto Show, bearing a brand-new face and an updated platform. Today our spy photographers have captured images of a stretched-wheelbase limousine variant in testing. Clearly sporting the new E-Class face, the limo spied is still in the earlier stages of testing, judging by the mis-matched character line along the side of the car. The car is believed to be a test mule for an upcoming long-wheelbase (LWB) variant. Little is thus far known about the car, but it can be expected to use the same running gear found throughout the rest of the new E-Class lineup, though likely only paired with the larger engines.