Over the weekend, AMG issued a sketch showing off the concept's rear and sides. We can see that the new car will be a sports liftback in the mould of the Porsche Panamera, while drawing plenty of styling inspiration from the GT coupe and convertible.
A report last month in Autocar claimed that just such a model would make its appearance at the 2017 Geneva show, although it was believed then that the concept would be branded as the GT4.
Sources have told the magazine that the GT Concept previews a second dedicated model line for the Mercedes-AMG sub-brand.
While the liftback and the GT coupe and convertible will share plenty of design DNA, it's said that the five-door GT liftback will not use the unique platform developed for the two-door GT range.
Above: Mercedes-AMG GT S coupe.
Instead, the new five-door will be based on the bread-and-butter MRA platform that underpins everything from the C-Class through to the S-Class. The GT will supposedly feature a unique footprint, as well as more lightweight materials, such as high-strength steel and aluminium.
Motivation for the Panamera-fighter will, unsurprisingly, come from AMG's ubiquitous 4.0-litre twin-turbo V8 paired, possibly, with a 48V electrical system, a small electric motor, and all-wheel drive. A cheaper six-cylinder turbo might pop up later.
If all goes according to plan, the five-door GT will begin popping out the end of the factory line some time in 2018.