At the time, we decided to stay clear of this hilariously unbelievable rumor for one simple reason. The Mercedes-AMG GT is based on an aluminum spaceframe that is closely related to the one from the now defunct SLS AMG. It's a front mid-engine with a transaxle arrangement, meaning that there is little space for two passengers inside the wheelbase. To make it a four-door, the spaceframe wouldn't need to be stretched but downright redesigned completely, which would mean that a lot of money would need to pour in such a niche product.
On the other hand, there is still an aura of mystery surrounding the third generation of the CLS, mainly because we are yet to see a pre-production prototype or even a development mule of the car, despite its unveiling date being just about a year away.
Well, it seems that there is an excellent reason for that, and it relates in a way with that somewhat unfounded GT4 rumor. You might want to take this with a small pinch of salt, but the third generation of the CLS is apparently set to become a Mercedes-AMG model, losing the “Benz” from its name and thus becoming the four-door brother of the GT.
Platform-wise, it is almost certain that it will be based on a heavily modified version of the aluminum-intensive MRA (Modular Rear-wheel-drive Architecture) that is currently used by the C-, E-, S- and the GLC-Class.
That said, since it may become an AMG-only affair, the CLS (X290) might only resort to the most powerful engine available instead of also coming in four-cylinder diesel flavor as it does now. On top of it, there is a new generation of turbocharged inline-six engines on the Mercedes-Benz horizon, most of them also coming with a 48-volt mild-hybrid system.
For those who think that the CLS would lose a lot of sales in Europe if it becomes a more exclusive Mercedes-AMG model, you should probably know that there might also be a CLE in the works. Apart from the name, the CLE would be the true direct successor to the current CLS, thus continuing the heritage started in 2004 and aligning itself with the latest Mercedes-Benz nomenclature.
On the downside, fans of the CLS Shooting Brake will have to say goodbye to the model after just one generation, since Mercedes-Benz has decided that despite its stellar reviews, the poor sales can only translate into a death sentence.