The real threat is foreign bad actors. There’s a global database that maps all VINs.
How many Americans have connected cars? How many are in garages? How many will not smell the exhaust before it kills them when every car in the country is started one night?
That’s WMD
Source: I used to meet with the CISOs of all the global auto manufacturers annually. If you’re a light sleeper, don’t work in infosec.