Is there a reasonable expectation of privacy operating a car on public roads?
People generally don't have a reasonable expectation of privacy in public. That's why you can record and photograph people in public whether or not they agree to be recorded. It's the same logic that makes red light cameras and parking license plate scanners legal.
Yes, there is a reasonable expectation of privacy while driving on public roads.
The expectation has been completely eroded by flock safety.