Your first two sentences seems to contradict one another.  The assumption was the cars would behave the same in tests versus how they are driven by real drivers, but THAT WASN&#x27;T IN THE TEST!  Test it! Randomly give them an 4 hour driving profile including resistance and acceleration generated from a model of drivers, fail if it diverges by X% from the reproducible baseline.  This is what people are complaining about (largely), but it wasn&#x27;t what was asked of the manufacturers.<p>Companies are required to act in the interests of the shareholders.  These companies were required to pass the synthetic tests.  If the manufactures spent precious resources &quot;wasting&quot; R&#x2F;D and manufacturing effort going beyond the requirements placed upon them to ship expensive but already conforming vehicles, they would be savaged in the markets, and executive open to litigation for dereliction.  I&#x27;m not defending it, by the way -- this is how capitalism works.