Premartial vehicle question

Ok I have a vehicle situation that I dont think I got a correct answer from the magistrate today. I have a 1994 truck that I let my oldest stepson drive. The title is my name and my first wifes name from 9 years ago. I have a power of attorney from my first wife to get it the title transferred to my name. The vehicle sat for 5 years and then I fixed it up for him to drive therefore I forgot about moving it over to my name. We are now separated for weeks and I want her to give me the title to sign it over to him outright or I want to go take the truck due to the liability of him having a wreck and hurting or killing someone since my name is on the title. The truck was a premarital asset but she did help with makin gsome payments on it over the years. There is no supervison with the kids now and they are running wild. Can I legally go get the truck or is it considered half hers (stbx)?