If they are accepting payments - that will reflect negatively on them if they try to take you to court on a deficiency balance, however they have the right to demand full payment of the loan at any time and take the car if you don't pay. Also - if you are just sending in partial payments that doesn't mean they are accepting them. They need to agree to the partial payments and how long it will go on. You can't stop them from repo by sending in some money every month.
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