Maryland Mass. Michigan Minnesota Miss. Missouri Montana Nebraska Nevada New Hamp. New York N. Carolina N. Dakota Ohio Oklahoma Oregon Penn. You may have to pay it before you can have you vehicle.
Mechanics often have excellent protection under the law.
If you chose the mechanic, then your insurer is likely completely within their rights not to pay the storage fees if such fees are outside your insurance contract. That's just not true at all. Used vehicles are notorious for having problems. You can refuse to pay, in which case I'm guessing the mechanic might be able to lawfully hold your vehicle until payment is received. Or you can pay or not pay and complain to an agency like your attorney general's consumer division.