The wife had a chance if she'd just called the police when it happened. Who would really just drive home, with him on the bonnet and carry on as normal?
Yeah this really wound me up. She could have just pushed him off of the bonnet and left. Who would possibly drive all the way home with a body on the bonnet? And she magically didn't meet a single other driver due to taking some "back route" home.
I think they still could have called the cops and said she drove the guy home so she could call him an ambulance, but then the guy attacked her husband and he killed him in self defence.
Also surprised she did not see the dead waitress lying in the snow as she looked at the diner.