Legal ways to collect your bill for auto repairs?

dubob wrote: "There may be some forms etc that will be accepted that the customer signs before the work is performed."

Oh yes, you can put an express (written) mechanic's lien in your work order and make the customer sign it, but if push comes to shove, I wonder if a city police officer or a county deputy sheriff would honor it and let the repair shop keep the car, as provided in the express mechanic's lien, or would they insist that you give the car back to the owner even if they don't pay, despite the express lien, and make you seek your payment in court?