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.

But the crowning glory is the Concept E’s heated gearbox oil, which helps reduce frictional losses when the car is first started.

Even better, the EU legislators - who are mostly trying to pick a fight with the EU car industry - have been put firmly on the back foot.