The blink-and-you’ll-miss-it star of the Paris show was undoubtedly the Audi A4 Concept E. 

European government is well down the road on demanding that the average CO2 output of a car maker’s range is just 130g/km – with promise of further cuts to come. As a result, some people in the industry wondered whether the day of the large car was over, and whether we would all end up in diesel-powered Ford Focuses.

However, the EU hadn’t figured on the might of the German auto engineer.

By applying a host of detailed fuel-saving measures, Audi has managed to turn its new A4 into a Prius-humbling fuel sipper.

The Concept E’s 105g/km CO2 (58.95mpg) rating has been achieved through some extremely clever lateral thinking. The 2.0-litre TDI engine gets new software, a new cooling system, de-coupling oil and water pumps and even softer valve springs. The stop-start system is backed up by a secondary battery, which powers the A4’s ancillaries when the engine is off.

The rear brakes are electrically actuated and the Concept E gets an aerodynamic underbody. Weight saving measures include a magnesium casing for the gearbox.