Novel-looking Mercedes-Benz prototypes, believed to be chassis mules for the next-generation SL, have been spotted - a week after AMG boss Tobias Moers told Autocar that SL prototype would hit the roads this year.

The prototypes show an E-Class saloon with a significant chunk removed from the wheelbase and body. The length and detailing of this chopped mule strongly suggests it is a test bed for the new shared sports car platform.

Moers confirmed last week that the SL, which will launch by 2021, will be “aligned” with the next AMG GT. Both cars will share a new aluminium-intensive platform, known internally as the Modular Sports Architecture (MSA), in an attempt to increase the economies of scale and overall profitability of two of Mercedes’ most exclusive model lines.

Autocar first scooped the new SL last October, but only recently has Moers gone on the record to confirm AMG's development of the new model. 

“We’re bringing back the historic DNA of the SL," he said. "It's far sportier [this time round]. It will have a perfect compromise between driving dynamics and comfort because it’s still kind of a cruiser too.”