Spotted along with a pair of oddly disguised GLEs, the spy video by motor1.com does not reveal much of Benz’s still heavily disguised flagship SUV allegedly heading for the North American International Auto Show in Detroit next month, aside from the non-standard taillights that has replaced the production clusters seen until now.

Aimed at the BMW X7 and incoming Audi Q7, the GLS will ride on the same Modular High Architecture (MHA) platform as the GLE and, aside from once again providing seating for seven, feature the same interior layout but, as recently seen, with a bigger take on the dual 10.25-inch MBUX infotainment system that debuted on the A-class.

Along with its new platform, the GLS  will make do with the same range of conventional and mild-hybrid turbocharged petrol and turbodiesel engines as the GLE and S-class, with the flagship expected to use the 4.0-litre bi-turbo V8 from the S560 that punches out 345kW/700Nm.

At the other end of the scale, the performance AMG GLS 63 will swap the long serving 5.5-litre bi-turbo V8 for the same 4.0-litre unit, but significantly revised to produce a claimed 441kW, the same as the 4.4-litre bi-turbo V8 used in the BMW M5 that will reportedly also power the rumoured X7 M.