Is it obligatory to pay off the remaining amount to the bank when selling a car that was purchased in installments from an Islamic bank, or is it permissible to continue paying the remaining amount in installments after the sale?

If the car is not mortgaged to the bank, there is no harm in selling it and benefiting from its price while continuing to pay the installments. However, if it is mortgaged, it is not permissible to sell it except by settling the bank's right promptly, because selling the mortgaged item without doing so would forfeit the bank's right to secure its money.