You'll live a much happier life if you let them have theirs, and decide on your own. It's okay for you to like your car and nixit not to. Really. You don't have to convince him otherwise, and in fact I can assure you that any attemtps to do so are wasted energy. So if you like what you've done with your car, just be happy for yourself. If you get defensive, it tends to make the rest of us think we've hit a nerve; that maybe you're not so confident of the choices you've made.