Nothing. He is 18, let him learn to do for himself. After all, he is dealing with his mother, right? So he can tell her that in order to put insurance on it, he needs the title in his name or else she has to put him on her insurance along with the truck. She has to do that or it won't be insured and if she doesn't want to deal with that, then she is better off putting the title in his name. Why? Because if she wants to insure the truck and not pay for him on her insurance, then when he has an accident, and you know he will...then it is gonna suck for her. She is better off putting the title in his name and letting you pay for his insurance like it seems you are willing to do.