Transfer of title from deceased to heir in CA

My grandmother passed last year. My dad has not been able to get her car transferred to him and has passed the task to me. He says he submitted the paperwork to the DMV and the DMV told him that their is a leinholder on the car in Oregon, and the DMV cannot tell him who it is. I am stuck trying to figure out what bank in Oregon is listed as a lienholder on the vehicle. The CA Registration does not list a lienholder, the spot on the paper is blank. I've tried some Google searches and I can't seem to locate any reliable information to take me to the next step in this process. There appear to be companies that I can pay for the vehicle history including the leinholders, but it all feels very scammy to me and I am leary of paying money and getting no further than I already am. Anyone have a clue what I should do next?