I would say that this is not the type of battle you want to engage in with your spouse. It's his truck -- for whatever strange reason, he's attached to it. Let him work it out. If he sells it, fine. If it doesn't sell, he'll figure out you were right without you having to rub his face in it.
When they say "marriage is hard work" everyone thinks the "hard work" is that you have to make time for each other and keep the romance alive, blah, blah. That's wrong. THIS situation is the hard work of marriage; recognizing when you should keep your mouth shut and let the other person muddle through.