So much for German reliability. Volkswagen has owned up to deliberately tricking diesel emissions tests with a neat little spyware device. Why do it? Nissan executives bowing in shame is nothing compared to some of the zinger apologies we have heard over the past 72 hours, but what will be the true fallout for the company, for the future of the diesel engine and for Germany's reputation as champion of green energy? Will it prompt wider soul searching about cheating the system in the digital age?