Not many new models that have come out in recent years have had the kind of impact on the automobile industry as the Mercedes-Benz CLS. Not only did it revive fastback design, but it also kick-started a revolution of sorts which saw the four-door coupé style proliferate into different segments including SUVs and crossovers. But while the rest of the industry took the idea and went to town with it, the CLS soldiered on without much change, with the last major update made back in 2012. Thankfully, Stuttgart is working on an all-new model, which our spy snapper caught testing yesterday.

There were rumours earlier suggesting that the next generation model will be renamed CLE in line with the brand’s new convention of naming models based on their platforms. However, we believe Mercedes will make an exception and retain the CLS moniker as this model is an icon for the brand.

These first spy shots show a prototype that’s heavily disguised. However, there’s no mistaking the classic sloping roof and the four-door coupé profile. Headlight and taillight graphics are visible suggesting this could be a near production-ready tester. Although there’s a Bangle-butt-like bump on the boot, we believe it’s merely cladding stuck on to mislead us. Although it shares its platform with the latest E-Class, it looks both wider and longer than the executive saloon. So rear-wheel drive with a standard nine-speed automatic transmission coupled with a 3.0-litre inline six is what we’re looking at, with an extreme AMG variant coming with a twin-turbocharged 4.0-litre V8 and all-wheel drive as standard, much like the recently launched E 63.

The third-generation CLS will likely get a debut later next year, with sales starting early 2018.