Mercedes-AMG GT4, artist's impression by Larson ► GT4 is next bespoke AMG sports car ► Aimed at BMW 6-series, Porsche Panam ► Here in 2019, based around next CLS Mercedes-AMG has a surprise for you: this GT4 four-seater, the follow-up to the sublime GT 911 basher which has so captivated us in the past year. Our artist's impression, published in the latest issue of CAR magazine (click here for a free preview), reveals the new four-door coupe due in 2019 to terrorise homegrown rivals the BMW 6-series Gran Coupe and Porsche Panamera. Merc-AMG GT4: the lowdown This car is based on the hardware of the next-generation CLS due in 2018; no body panels will be shared, but the power brokers of AMG will take the fundamental architecture of that car and redress it for a sportier, more focused mission. Much of the bodywork is crafted from aluminium to keep weight in check. Expect shorter overhangs - our sources suggest it will be 100mm shorter than a CLS - but it remains a ...