A power of attorney is only good while a person is alive, so no, it will do you no good after your husband dies.  If your husband is still coherent, the best way to get you the car is for him to leave it to you in a Will.  If he is not, and he has no children from any other relationship, then you will inherit the car anyway under the law in Ohio.  In Arizona, likewise, the wife inherits everything.  However, if he has children by another woman, you will have to share the inheritance with them under Ohio law.