Amid the hubbub created by the launch of the latest AMGs – the standalone GT 4dr Coupé and the new G63 - you could be forgiven for not noticing a rather demure-looking C-Class saloon on the Mercedes-Benz Geneva show stand.

Indeed, you might not realise there was anything different about it at all, unless you went round the back and saw that it was badged 300de. Is that for Deutschland, perhaps? It is not; it stands for ‘diesel electric.’

Mercedes’ solution to the crisis facing diesel cars is not to expunge them from its ranges but to use technology to adapt them so that their shortcomings are effectively ameliorated. And that means not just a diesel hybrid – for such things have been made before and by Mercedes, among others – but a plug-in diesel hybrid.