I'm not going to offer to pay the diminished value of my son in laws truck I wrecked
Why do you think that you won't pay for it?
Because he deserved having his truck wrecked.
I don't know why you decided to destroy your son in law's truck, but it is never okay to do that to someone else's property. You need to be responsible and replace the truck, because your son needs it.
I don't know about that.
I think that you should replace the truck since you were the one that wrecked it. It is only right that you replace the items that you have destroyed.