The US and China go to war, over Taiwan say. This would be part of a general attack on the US, and would include things like the power grid, internet infrastructure, and anything else that can be disabled or turned against us.
Terrorists decide that 9/11 wasn't good enough, and they can do 1000x more damage, death and terror from the comfort of their computers.
Extortionists decide to leverage this capability to extort money from car companies.
More targeted killings would be motivated according to your thought.
This is just the top of my head. I'm sure there are others.
It just seems like the degree of premeditation involved here would also come to the conclusion, given how over invested we are in our military, that is better to make it seem like the US is perpetually shooting itself in the foot rather than make it seems like the US has been shot. We tend to get all rambunctious when we know it was an attack, better to have us lose the war before we know we're fighting it.
When it comes to remote vehicle access I think you could do more damage carefully over the course of a decade than you could do rashly in a day.
I think Taiwan is the most logical short-term thread model that could lead to widespread cyber incidents internally.
Other continues be something like NotPetya, localized cyberwar tactic that hits public internet and runs amuck. But to get from that to critical infra in US, let alone personal autos, is hard to picture.
The US and China go to war, over Taiwan say. This would be part of a general attack on the US, and would include things like the power grid, internet infrastructure, and anything else that can be disabled or turned against us.
Terrorists decide that 9/11 wasn't good enough, and they can do 1000x more damage, death and terror from the comfort of their computers.
Extortionists decide to leverage this capability to extort money from car companies.
More targeted killings would be motivated according to your thought.
This is just the top of my head. I'm sure there are others.