Forget about that stupid mini-van on the highway that was going 40 mph in a 65 mph zone. Forget that you got stuck behind this dumbass. Forget that you couldn't get around them because the traffic is whipping by at 65 mph and you're only going 40!
Let it go. Your truck doesn't have an RPG launcher and even if it did, you would get into a lot of trouble if you blasted that minivan into pink mist. Besides, if you think about it, should idiotic driving be considered a capitol offense? Shouldn't there at least be a trial or something? Besides, I'm sure there was a time or two when you were the idiot...
When you could, you got around the mini-van and you moved on with your life. You're home now, no more driving until at least tomorrow. The chances of you crossing paths with the 40 mph idiot again is very slim.
So why are you still angry? Get over it.