Yes, there are huge national security concerns when everybody's cars are always on the network and all fly-by-wire. It would be trivial for anyone who writes the software for these things to include logic or network bombs in them that would enable a catastrophic strike on a country or the rest of the world. Cars being on the network all the time is really a terrifically stupid idea.
Careful readers may note the complete lack of the word "China" in the previous paragraph. But, yes, technically it is even that much more dangerous to have a whole bunch of potentially-hackable robots roaming up and down all your transportation corridors that were also created by your major economic and military rival.
But I don't even like it when it isn't created by your rival, though, because there's no guarantee that your rival can't hack anybody's software. I fear the day when some significant fraction of cars on the road are given instructions to floor the pedal and then do a hard turn to the left 10 seconds later. (Or the right for countries where that is the "turn into oncoming traffic" direction.)
Careful readers may note the complete lack of the word "China" in the previous paragraph. But, yes, technically it is even that much more dangerous to have a whole bunch of potentially-hackable robots roaming up and down all your transportation corridors that were also created by your major economic and military rival.
But I don't even like it when it isn't created by your rival, though, because there's no guarantee that your rival can't hack anybody's software. I fear the day when some significant fraction of cars on the road are given instructions to floor the pedal and then do a hard turn to the left 10 seconds later. (Or the right for countries where that is the "turn into oncoming traffic" direction.)