So if the testers didn’t know that the “feature” was there then they wouldn’t have tested it and it’s unlikely they would have tripped over it – given that it is apparently designed to only kick in during a very specific set of circumstances (e.g. going at test speed, no input from the steering wheel, certain pressures in the system and so on). In fact, the engine was probably tested in isolation. So the only people who would have noticed the good performance would be the technicians getting the stats for the finished car who would have attributed it to good overall engineering rather than cheating software.

Really, apparently this thing has been there for years and no-one has noticed it until now so it must be pretty well hidden. None of the regulatory testers saw it, nor the techs who service & maintain them, nor the people who mess with the ECM to get better performance from the cars. I bet car companies take their rivals cars apart to study them and they didn’t see it either – or maybe they did and kept quiet because “there but for the grace of God go I”. But even then it would have leaked before now as one company tried to gain advantage by smearing another.

I’m not saying all this is excusable, but I can understand how this sort of thing happens because plain old human nature means that we take the easy route. As a race we are fundamentally lazy and we keep falling over ourselves because of it. Always were, always will be.