The Mercedes BLS – essentially a smaller version of the CLS four-door coupe – has been spied winter testing ahead of its unveiling later this year.
The bodywork is hidden under heavy cladding, but the model's sloping bonnet and upright grille reveals it will get a look inspired by the F800 Style Concept.
Aimed at upcoming models like the all-new Audi A3 saloon, the BLS is based on the same chassis as the new Mercedes B-Class. That means interior space should be generous, with seating for four adults.
Under the bonnet, drivers will find an all-new 1.6-litre turbo petrol engine, with either 120bhp or 154bhp, and a lighter, more efficient 1.8-litre diesel that will also be ofered in the E-Class and C-Class this year.
A high-performance AMG model is also on the cards, and will reportedly use a 2.0-litre turbocharged engine producing around 260bhp.
Sales of the BLS will kick off towards the end of 2012, with prices starting at around £25,000.