Mercedes spotted testing new S-Class cabrio in the snow

A fullsize luxury convertible is a rare species. There's the Bentley Continental GTC, maybe the Aston Martin DB9 or Vanquish Volante and the Maserati GranTurismo Convertible if you won't need those rear seats too often, but that's about it. The segment seems to be expanding, though, with the imminent arrival of the drop-head version of the Rolls-Royce Wraith and the new challenger you see here.

Spied undergoing winter testing in Sweden, this prototype for the upcoming Mercedes-Benz S-Class Cabriolet is wearing barely any camouflage or body cladding whatsoever. In all likelihood that's largely because it's essentially the S-Class Coupe we already know, but with a folding fabric roof: Mercedes typically keeps the origami tin-tops to two-seaters like the SL and SLK.

When the new S-Class cabrio is ready to launch – probably sometime between now and the summer – it'll join an expanding array of convertible Benzes that already includes the aforementioned SL and SLK and the E-Class Cabriolet, and will soon adopt the AMG GT roadster as well.