Sometimes it strikes me that the most significant progress is the kind that nobody really notices.

I spent my Christmas break in a VW Passat Bluemotion, complete with the new 104bhp 1.6-litre VW Group commonrail turbodiesel engine.

Volkswagen Passat S 1.6 TDI Bluemotion first drive

There is nothing headline-grabbing about this car.  It does not have a fuel cell, solar panels or an electric motor anywhere under its decidedly bland exterior, and it is not made entirely out of recycled potato and hemp.

It is a normal family saloon with a low-powered turbodiesel engine under the bonnet. But it took me and the other half to see family in Koburg, Germany for New Year in perfect comfort whilst easily achieving over 800 miles to each 70-litres of fuel.

That still means we fell short of the claimed 62.8mpg combined figure, but we did manage mid-50mpg for much of the trip and there was no compromise in the overall capability of the car. It was quiet, spacious and pleasant to be in. And it was cheaper and more convenient overall than catching a plane and picking up a rental special at the other end.