Boasting updated exterior styling and overhauled cabins, the cars were caught winter testing in Germany wearing only light camouflage.
Design tweaks include revised front and rear bumpers plus changes to the front and rear lights, with the shooting brake to get a redesigned front grill.
Inside, the cabin cops a redesigned steering wheel and an updated infotainment system. Engines are likely to be carried over from the current model lineup which is headlined by the twin-turbo 5.5-litre CLS 63 AMG S churning out 430kW/800Nm.
Sign up here to receive the latest round-up of Wheels news, reviews and video highlights straight to your inbox each week.
Want free access to 5 years of Wheels archive content? Sign up now!