Mitja Borkert introduces the Panamera Sport Turismo concept at the Paris auto show.

It's not often we get the chance to see what goes on inside the design department of a major carmaker but today Porsche head of design Mitja Borkert takes us through the development of the Panamera Sport Turismo concept, built for the Paris auto show.

Borkert said: "The Panamera has one body style today: a four-door coupé. But we were intrigued by the idea of developing another version for Porsche, a sports station wagon."

Which was by no means as simple as it sounds.

It had to both sporty and practical and, above all else, Porsche-like. To complicate matters further, the Panamera Sport Turismo is a runner, as are all Porsche concepts, with a plug-in hybrid set-up combining a 245kW supercharged three-litre V6, a 70kW electric motor and a 9.4kWh lithium-ion battery, for a total of 306kW, taking it from 0-100 in less than six seconds while averaging 3.5 litres per 100km and emitting less than 82 grams/km of CO2.