Unfortunately in my game they were consistently crashing the application. I disabled them and haven’t had a crash since.
It’s too bad though, they did make for fun encounters. In one game I talked one into joining me. I was impressed when he hopped in my car. I was impressed again when he asked me to pull over so he could pick up a rock (he was unarmed) and he came back into the car. Unfortunately when I drove into town and ran over a zombie he turned on me and started punching me from the passenger seat.
So I’m driving 60mph with a horde of zombies coming, dodging cars with a lunatic passenger. I manage to kill him but not before I crash the car and get eaten. It was a crazy death. I’m not sure if him turning on me was a bug or if he was just a dick.
Since then my game would crash every time a npc got near