What is the ruling on taking a loan to buy a car without interest, given the existence of a fixed and predetermined penalty clause that the debtor pays in case of遅延 (delay) in repayment to cover debt collection expenses?

Every stipulated increase in a loan contract is prohibited usury (riba), and it is impermissible to stipulate the payment of a fixed amount to cover collection expenses when payment is delayed, because this is clear usury, whether the debtor is in straitened circumstances or procrastinating.

As for the debtor in straitened circumstances, he must be granted a respite until he finds ease, and it is not permissible to demand the debt from him or burden him with any increase.

As for the procrastinating debtor who is able to pay, the creditor may burden him with the actual collection expenses incurred by the creditor due to the debtor's procrastination, but it is not permissible to stipulate a fixed financial compensation.