I'm expecting more ransom ware "bricking" cars than causing accidents.
1st week: "windscreen wipers and air conditioning are disabled until you pay 5 bitcoins"
2nd week: "speed is limited to 30mph until you pay 10 bitcoins"
3rd week: "your car won't start until you pay 20 bitcoins"

Way less incentive for law enforcement to come after them when they go for people's money instead of everyones safety.