Captured by the walkoART YouTube page in prototype, non-AMG guise, the imposing looking GLS is still hard to make out thanks to heavy amounts of disguise and pre-production body panels, but expect it to mirror the smaller GLE in production-spec.

The most intriguing though are new shots of the interior, which suggests the fitment of a new dashboard as the partially covered panel houses a bigger adaption of the dual 10.25-inch infotainment display and digital instrument cluster, which will likely receive the MBUX software that debuted on the A-class.

Reportedly due to make use of a new platform, the GLS will come powered by the same range of turbo-petrol and turbodiesel engines as the GLE and S-class, namely the 270kW/560Nm 3.0-litre straight-six in 450 designated model, the 4.0-litre bi-turbo V8 that makes 345kW/700Nm in 560 badged variants and the EQ Boost equipped mild-hybrid straight-six from the GLE that punches out 270kW/500Nm, with an additional 16kW/250Nm available for short bursts.

Diesel power will be limited to the internally named OM 656 3.0-litre straight-six that offers either 210kW/600Nm or a mammoth 250kW/700Nm. As previously mentioned, the AMG GLS 63 will drop the long serving 5.5-litre bi-turbo V8 for the 4.0-litre motor mentioned above, but allegedly revised to produce 441kW, the same as the 4.4-litre twin-blower V8 used in the BMW M5 that will allegedly also find its way into the rumoured X7  M.

Based on current speculation, the GLS could make its world unveiling as early as January at the North American International Auto Show in Detroit, although this remains to be seen.