The specific process may vary from State to State and you may inquire at your motor vehicle registrar to se exactly what format is correct for yours.
However, I think it is best to explain that, unless the court orders it to be done as part of a way to secure a judgment (after you have gotten the judgment), placing a lien against a motor vehicle (becoming a lienholder), would be something the titleholder has to agree to allow. When purchasing he puts the bank in that position, if the car is collateral, he basicallys retitle it with a named lienholder.
You cannot simply grant yourself a secured creditor status by placing a lien against someones car because you believe, even very rightfully, that you are owed money.
Because it is not fixed property the only way to do that is to show you have some type of ownership in it and get it repoed and sue the person for the monies. You cant put a lien on the car if you don't have a vested interest in it. Like a bank or a car dealer. If you have a written agreement with this person to pay you for the car or your name is attached to the car and you are paying for it but this other person has it, the above remedy is your answer.
The recording of a lien perfects your interest in the property. Giving someone a loan for a car, but NOT establishing the car as security for the loan by being named as lienholder as a condition of the loan and having it recorded, does not mean you have any specific interest in the car. You don't. You are only a general creditor.
I also don't see where the issue of possession of the property, regardless of the unsecured or perfected agreements for the re-payment of a loan, makes a difference to the establishing a lien. And as mentioned, if your name is actually already "attached to the car", as titleholder you have a more substantial interest than lienholder. Trying to get a lien on your own property, essentially against yourself and for yourself at the same time, has no benefit and makes no sense.
Note: The above was a response when the Q was worded differently. The first response is a good answer to how it is now worded.