Replaced a bad head gasket and brakes all around the car was being financed any to get the money owed or get the car

Not likely. Since the car was being financed there is a prior lien on it. So even if you file a mechanics lien, if the car is repossessed its unlikely you would get paid. Your best bet is to file a law suit against the owner.

I don't believe you can file a mechanic's lien on a car anyway. Mechanic's liens are for real property, strangely enough.

Do you still have the car?