SPY PICS: Benz prepares all-new S-Class for 2020

The Scandinavian winter was the backdrop for this next-gen Mercedes-Benz S-Class spotted on test in prototype form as engineers prepare the new limo for its launch in 2020.

Believed to be the first glimpse of the next Benz flagship, the photos indicate it will be proportionately similar to the current W222 series, with recognisable styling cues in the curvaceous profile to include the familiar arched lower side window lines and the dropaway boot.

For all this, the upcoming S-Class will be essentially all-new, with a fresh rear-drive platform - dubbed MRA - that should give the big Benz a slightly longer wheelbase, along with wider tracks, for a larger interior. Apart from those points of difference, the overall proportions are not expected to change - although weight reductions, courtesy of the new platform, are on the cards.

That said, these may be offset by the added technologies, including autonomous capabilities, that are anticipated to be ushered in with the new model.

Rumour is that these sophisticated self-driving features could facilitate the car driving itself and leaving the driver fee for (limited) extraneous activities.

It is also being mooted that the S-Class will feature electrified drivetrains across the board, using regular and plug-in hybrid technology. A fully-EV version is certain to appear a little further down the track, once Benz adequately addresses space problems associated with large battery packs. Base engines are said to include new-generation inline sixes, and developments of current-series V8s.

Gossip mongers are also suggesting that S-Class coupe and cabriolet variants won't make it into the new-generation cars. It has been suggested a four-seat version of the next-generation SL-Class will step in as a substitute.

What has often been dubbed as the best sedan car in the world isn't about to let go of its status.