My understanding is that diesel cars had to be manufactured with either a NOx storage catalyst or injectable urea, both designed to convert the NOx emissions into something less harmful. What VM did seems to be the equivalent of just removing the catalytic converter.

It beggars belief that the ceo and many executives were unaware. Considering that, in order to make emissions standards, competitors have to add hardware to the emissions system or inject urea, which increases costs and hassle to the driver (you have to fill the AdBlue, every piece of hardware is a maintenance cost waiting to happen) and to VW (plumbing, harder to convince drivers to buy diesel.) VW figured out a way to avoid both, a distinct advantage to their diesel products. And nobody in the executive team inquired at all how this engineering miracle they pulled off worked? I don't believe it. If nothing else, someone in the executive team asked how long it would take their competitors to copy VW's innovation. Or suggested patenting it.