I submitted the Idaho Motor Vehicle Record Request, which includes a list of possible reasons for allowing them to disclose personal information. Because the DT had been given to me without a title, I requested the current titled owner so I could contact them to release the title. Unfortunately, I was unable to contact them, but I was able to show that I tried so I was issued a "conditional" title for three years. If the titled owner comes forward before that three years is up they could try to take the DT from me. I'm pretty sure that they wouldn't be able to since it's been in my possession for over a decade, but...
Anyway, I also have another PDF that outlines how to request infromation for each state. I can't find it online again, but I sent it to you in a PM. Do you know which state it was registered in?
Good luck!