After a shopping spree in the 1990s, which saw the BMW Group acquire the California based industrial design studio DesignworksUSA, the British Rover Group and the rights to the Rolls Royce nameplate, the Bavarian company cooled down and focused on building up the range of its three core brands: BMW, MINI and Rolls Royce while selling off MG Rover.

Today, the BMW brand already comprises of two unique sub-brands developed under the M and the "i" monikers for its high-performance and for its electric cars, plug-in hybrids and other alternative-power vehicles respectively.

But the Bavarians aren't done yet as following the example of Audi and it's S range that slots between the regular and RS models, they are readying a third sub brand called M Performance that will be positioned under the automaker's M models.

It's no secret that BMW intends to market a whole line of advanced dedicated hybrid, range-extended and plug-in electric models under its new "i" sub-brand.

The question is, what's up next after the presentation of the i3 hatchback in 2013 and the i8 sports coupe in 2014? While BMW is keeping mum about its future plans, our spy photographers captured a strange looking 7-Series prototype, seemingly based on the standard ActiveHybrid 7.