A prototype has been caught on one occasion in the past by our network of spies and here comes the latest shots for your enjoyment.

The current generation Mercedes E-class was thrust upon the world in 2009 and Mercedes' engineers are readying a mid-cycle update in time for 2013. 

The updates focus on the front and rear ends which are heavily camouflaged in these pictures. The restyled E will receive a new grille with fewer horizontal chrome bars and will also house the Mercedes-Benz star on the center, much like the new A-class. The headlights and bumper will also follow suit with the A-Class's styling as a template. Meanwhile, the rear will not be ignored completely. Expect to see remodeled tailights that incorporate repositioned reverse lights as well as a new rear bumper.

The engine range will be enhanced with a new entry level E200 model that will employ a Renault-sourced 1.6-liter four-cylinder unit generating around 156bhp (116kW / 158PS). Further up the scale, rumors state the E350's 3.5-liter V6 engine will produce 333bhp (248kW / 338PS) while the E500 will get a new turbocharged 4.6-liter engine producing 435bhp (324kW / 441PS) and 699Nm (516lb-ft) of torque.