Don't know if you've noticed but BMW seems to have been burning the midnight oil recently in an effort to lop the roofs off on as many of its cars as possible. Last month's Geneva show was proof positive of this trend, with the Mini Convertible making its debut alongside the Rolls-Royce 100 EX concept - a shortened soft-top version of the gargantuan Phantom. And if that wasn't enough, BMW's engineers have now taken their angle grinder to the 6-series.

Taking the excellent Coupe as the starting point, the roof has been lopped off and in its place is a triple-layer fabric hood with a special insulating foam sandwich.