It a growing trend amongst vehicle manufacturers. No longer do we just get to see the finished product. We are coaxed to imagine it, dream it and expect the unexpected.

Volvo's recent unveiling of its C60 is part of this trend and now BMW has jumped on the wagon with its own teaser concept.

It's an advert for the next-generation 5 series sedan, which features a ghostly outline of the vehicle, but doesn?t fully reveal it.

The idea behind the advert, BMW says, is to "hint at the sporting and elegant design of the new BMW 5 Series Sedan, using the kinetic sculpture from the BMW Museum to create the silhouette".

Fitting in neatly between its 3 and 7 series kin in a styling sense, the 4.86m long new 5 model brings some interesting new technology along, too.

This includes an all-new, 230kW biturbo direct-injection, 3-litre petrol engine, a 185kW 530d and a 125kW, 4.1l/100km 520d and BMW's superb 8-speed automatic transmission with start-stop system.