Far from 'just another show car' the BMW CS represents no less than the next stage of the German marque's design direction. Unveiled at the Shanghai auto show, the four-door Gran Turismo 'concept study' may pave the way for a new niche range-topper for the brand - it is longer than the 7-series, but lower and with a long 3.1 metre wheelbase - but it is more important for the new design features it showcases that could make production on future BMWs of all shapes and sizes soon.