The best part of a BMW Design Night at the 2010 Beijing automobile show was this outstanding four-door theory.

It is a typical BMW shape with an extended wheelbase, vaulted bonnet with forward-pointing lines, set-back greenhouse, coupé-style roof line and short front overhang.

Elegant lines dictate the silhouette, while stretching the entire length of the car, which is approximately five meters, but the characteristic, strong BMW sill line has been lost. Frameless doors hide the B pillars to provide the look of a flawless glass surface.

The roof is less than 1.4m high, 100mm lower than, either the 5 or 7 Series cars and diminishes tenderly to the back to make the sedan look even longer whilst a forward-tilted shark nose visually expands the bonnet.

The classic kidney frame is visually divided from the headlights and lower air inlet, which is extended approximately near the corner areas in order to highlight the car's breadth.

The rear lights and tailpipe trims lead the rear view, until the driver pushes the brake pedal and the high-mounted, LED, third brake comes on, lighting up the entire breadth of the back window.