Thankfully, hopefully, Fred is not too likely to actually do that. And, God seems to be answering prayer that Fred work more earnestly at laying aside such rage. It does show up across the board in the rest of his life, too--though most pointedly and persistently when driving.
But it's been and remains a huge struggle--very tied to Fred's incredible levels of pride.
And this is a truly very bright--genius level, earnest, authentic Christian engineer. He's on his 3rd marriage, IIRC. His flawed wife used to drive him almost daily to extreme distractions as a minimum, with her imperfections.
Finally, God has increasingly succeeded at mellowing things out on both sides of those sorts of problems.
Yet the bulk of his enormous, vain pride and perfectionism remain--along with his road rage. At least now, he's more humble about realizing it and seeking prayer for it. He may even be starting to change. He doesn't want another stroke.