I'm pretty sure that driving a car that has to be restarted in the middle of an intersection is more dangerous.

Safer than the car that shuts off in the middle of the highway due to a software update?

One other thing I remember is that you were always on the alert for the car in front of you suddenly bricking itself, due to a "hardware update."

I'd look at the accident stats, which I honestly don't know. But my hunch is that the newer cars are safer.