When a mechanic performs work on a vehicle and the owner fails to pay for the services, the mechanic may hold the vehicle and place a mechanic's lien on it. If the owner fails to pay the bill within a statutory time period then the mechanic may sell the vehicle to satisfy the lien. State law will differ with regard to time frames and exact procedures but the basic process is similar in all states.
Research the specific laws of your state as they apply to a mechanic's lien for a vehicle. A good place to start is by contacting the Bureau of Motor Vehicles as that is where you will need to apply for the title in the event you sell the vehicle.
Document the services performed and the total amount due from the owner of the vehicle. Most jurisdictions require a detailed work order showing the work performed as well as an itemized statement showing exactly what the owner was charged.
Notify the registered owner of the charges due and your intention to place a mechanics lien on the vehicle and/or sell the vehicle at auction. Most states require that the owner be notified by certified mail at least 30 days prior to any attempt to sell or dispose of the vehicle.
Publish the lien in a local newspaper according to the local requirements. You are also generally required to publish at least 30 days prior to selling the vehicle.
Complete the mechanic's lien affidavit or similar document used in your state and required by the Bureau of Motor Vehicles in order to obtain a title. When you sell the vehicle to satisfy the mechanic's lien you will need a clean title for the buyer. Most states require that you sign an affidavit or affirmation attesting to the work done, amount due and that you have followed the required procedures.