These latest test cars, caught testing in Europe this week, reveal that the new C-Class will mix elements of the new A-Class and B-Class models, along with the 'smaller' CLA sedan and the new new S-Class limo.
Handling, performance and comfort will also be major points of improvement, in the hunt for new buyers.
“We want once and for all to discard the idea that the C-class is a car bought by your grandfather, ” an insider reportedly told Britain's Autocar.
“We have gone to extensive lengths to ensure it will meet the expectations of a younger generation of buyers, both visually and technically.”
The carmaker will also introduce a number of new and 'trickle-down' technologies to the C-Class, as it works to steal sales from BMW's top-selling 3 Series range.
Expect a range of new internet connectivity features and top-shelf safety systems, including new collision avoidance technology (also featured in the updated E-Class) and automatic parking.
The new C-Class will be larger and lighter - by around 70kg - riding on the carmaker's modular new rear-wheel-drive MRA platform, which will also sit under next-generation E-Class models.
The steel monocoque architecture focuses on weight-saving and rigidity, contributing to fuel efficiency and ehanced driving dynamics. According to Autocar, a new C 160 variant will weigh less than 1380kg.
Expect an advanced new double wishbone suspension design up front, and an overhauled multi-link arrangement at the rear.
Adaptive damping control is also expected, along with a new electro-mechanical steering system.
Engines in the new C-Class will sit lower and further back for improved centre of gravity and weight distribution.
Options will include four-cylinder and V6 petrol engines ranging in power up to 245kW, and an upgraded version of existing diesel choices is also expected.
Depending on specification, six-speed manual and seven-speed automatic transmissions will be available at launch, with ZF's coming new nine-speed automatic to follow.
Rear-wheel-drive will remain the standard configuration, but a new driveshaft layout will allow for 4Matic four-wheel-drive variants to be offered in both left- and right-hand-drive (an approach which also cover the next GLK SUV).
Sedan, Estate and Coupe bodystyles are confirmed, and a new Cabriolet model has been reported.
The new C-Class is expected to make its international debut at the 2014 (yes, 2014) Geneva Motor Show.