Are the remaining car installments the responsibility of the deceased father or the son, and is it obligatory to pay the entire remainder despite discovering defects in it after the purchase?

Lease-to-own may be permissible or forbidden. In such a contract, the lessee is the one responsible for the debt. If the father leases a car for his son in his own name, the father is obligated to pay. However, if the son is the actual user of the car, then the son is the one obligated to pay. If the bank waives the installments for the father due to his death, then the son must inform the bank that he is the real lessee. If there is a defect in the car, the son has the option to either reduce the rent or the price, or to terminate the contract.