As CarAdvice revealed earlier this year, the new GLC63's drivetrain will be derived from the one that will be used underneath the upcoming E63 sedan and wagon, rather than the one used in the existing C63.
All of these vehicles, as well as the Mercedes-AMG GT coupe, amongst others, use the AMG tuning house's latest-generation 4.0-litre twin-turbocharged V8 engine.
A leaked Russian dealer brochure claimed that in the new E63 the 4.0-litre motor will crank out 420kW of power and 750Nm of torque, while the E63 S will be tuned to deliver 450kW of power and 850Nm of torque.
If this leak proves to be accurate, even the base E63 will boast more power and torque than the current most powerful version of the 4.0-litre twin-turbo V8, which has a 'mere' 375kW/700Nm to its name.
The new E63 and E63 S will come standard with a nine-speed automatic transmission, air suspension and an electronic-locking rear differential. Expect all-wheel-drive to be standard on the new GLC63.
Visually, the new GLC63 is differentiated from its less powerful brethren by a fatter wheel and tyre combo, as well as a more aggressive front-end treatment with a new bumper sporting the large lower air intakes common to the current Mercedes-AMG range.
Out the back there's aerodynamic modifications to the wheel arch flares, a new rear bumper, and while this prototype features bifurcated exhaust tips like those on the GLC43, the GLC63 will almost certainly sport the squared-off quad-pipe treatment like the rest of the full-fat AMG line-up.
Given that the only area disguised by camouflage tape is the front apron, we expect the Mercedes-AMG GLC63 to debut by the end of the year, at the latest. That means that it will probably go on sale down under some time in 2017.