Humm.  A release of lien is also known as a satisfaction of the loan.  This document needs to be filed and then yo will need to obtain  a clean title to your car.  If you think that it is a mistake then you are very wise to be cautious about it all.  It will catch up with you should it be a mistake.  In the meantime, I would not be a spendthrift with the loan payments that you think that you owe.  I would can  and ask for a complete history of the loan including all payments (you are entitled) and I would ban the payment sin a separate account just in case.  Good luck.