Really? Do you imagine the only thing stopping people from trying to kill random strangers is the fact they currently have to get up out of bed to do it? Because it can't be the fear of getting caught, since the perpetrators of any vehicular malware that kills people will be caught...

If the fear of getting caught prevented people from committing crimes, jails would be empty.

Exactly, so according to the people worried about killer malware, the only thing stopping our population of latent murdering sociopaths is the fact that it's currently too much physical effort to go and sabotage some sandom vehicle? As I said, this seems unlikely to me...