I think a more pernicious problem would be if cars could give themselves an advantage - influencing routing algorithms, blocking cross traffic, favorable light

I think a more pernicious problem would be if cars could give themselves an advantage - influencing routing algorithms, blocking cross traffic, favorable light changing, warning cars away. There used to be a device that could mimic an emergency vehicle entering an intersection which would create a green light, and that is the kind of thing people would use, to the detriment of others.