As Mercedes-AMG marks its 50th anniversary this year, the debut of its F1 race car-based, limited-run hypercar will be accompanied by the Mercedes-AMG GT4, a four-door version of the AMG GT sports car. Where the AMG GT was built from a modified SLS AMG platform, the upcoming four-door version is rumoured to adopted the modular, rear-drive MRA architecture instead.

The AMG GT4 aims to take on the sleeker-roofed, high-performance four-door establishment which includes the likes of the Porsche Panamera, BMW M6 Gran Coupe and the Audi RS7; the new Mercedes is tipped to be the successor to the CLS Shooting Brake, according to an Autocar report.

Following its expected Geneva debut in March, the production-ready GT4 is rumoured to reach the European market next year, in line with earlier estimates of a 2018 debut. As with the two-seater GT, the GT4 is expected to be available in two variants; a standard model and an ‘S’ version, the latter tipped to surpass the 600 hp of the Mercedes-AMG E 63 S.

That output advantage could possibly come from an integrated starter generator (ISG), which is tipped to take residence in the GT4’s transmission for temporary boosts of 20 hp, drawing power from a 48V electrical system; the production model could also feature a lithium-ion battery of “moderate size.” AMG’s 4.0 litre twin-turbo V8 could also be joined by Mercedes’ new 3.0 litre inline-six, also with ISG assistance.

GALLERY: Mercedes-AMG GT C Coupe