Our spy photographers have managed to capture the next-generation Mercedes-Benz C-Class (codename W206) undergoing testing again, this time in the form of a plug-in hybrid version.

As with a previous development car, the latest one seen here wears quite a bit of camouflage to hide its body. At first glance, the design of the new car appears to be an evolution of the Sensual Purity philosophy, with less prominent creases and slimmer headlamps.

According to our source, the vehicle’s charging port is now located on the left-side rear fender instead of the rear bumper like on the W205 C 350 e and C 300 de. Of course, the exact specifications of the new C-Class’ plug-in hybrid powertrain remain a total mystery for now – petrol and diesel versions exist.

The W206 is said to be built on a new version of the Modular Rear Architecture (MRA2), which is claimed to provide more space for passengers. On that mention, the interior should also get many of the technologies from recent models, including the Mercedes-Benz User Experience (MBUX) that was given a miss with the W205 facelift.

A selection of engines augmented by a 48-volt electrical system parked under the EQ Boost umbrella should be a norm as well. These include the M264 turbocharged four-cylinder petrol powerplant introduced on the facelifted W205, which comes in 1.5 and 2.0 litre displacements.

Other engines that are likely to be in the line-up include a 3.0 litre mild hybrid twin-turbo straight-six for the AMG C 53, which substitutes the C 43, while the C 63 should get the familiar 4.0 litre biturbo V8.