That's the key question: whose laws are Waymo enforcing? ICE and Flock's extra-constitutional policies? City ordinances? A future eco-radical government's laws?
How about things taking place outside the car?
Can Waymo mount a robotic machine gun next to the LIDAR and snipe suspected terrorists? Release tear gas? Self destruct, killing several nuns to protect s CEO?
Btw ghost guns are not all instantly illegal.