BMW will set the cat among the pigeons (again) next year when it slides the covers off a radical new crossover.

It’s not the first time that the masters of Munich have launched a perplexing car – remember those radically designed early Bangle cars? – but the so-called Progressive Activity Sedan is likely to set most bystanders scratching their heads.

You see, the PAS is part family estate car, part smart luxury saloon and part off-roader. It’s no wonder it’s hard to pigeonhole. And, word is, it will look rather odd underneath all that cladding used by the engineers to disguise this prototype – like a 5 Series Touring on stilts, according to our Munich sources.

Spies caught this test car on a shakedown evaluation in Germany. Its sloping tailgate reveals a fastback rear, which hides an unusual secret. The boot has a novel hinge system that lets owners choose whether to open the full tailgate (like on a regular hatchback) or just the rearmost section (like on a traditional saloon). The seats are raised and the rear pews adjust individually.

The PAS will stand slightly taller than the 5 Series Touring whose mechanical underpinnings it shares. Most models will be rear-wheel drive, but 4WD versions will be available too, while the usual, broad range of BMW engines will stretch from a 245bhp 3.0-litre diesel to a 408bhp 4.4-litre petrol V8.

Design
BMW 5 Series Touring meets off-roader. Unusual twin-hinged tailgate

Timetable
On sale in 2009, priced from £40k

Technology
Full suite of direct-injection petrol engines, diesels and stop-start tech.