Driver facing camera systems can be consistent with privacy, as long as they don't record or transmit any data other than a single dimensional metric of how distracted or drowsy a driver is (or even discrete binary state of yes/no) and timestamps when that state was detected.
A closed loop system that merely keeps that data for the current drive and maintains it solely in the vehicle's own systems can be consistent with privacy principles that nobody else should know anything about how a car is being used, except what can be observed from the outside.