Is it permissible to buy a car in installments from a dealership that requires a bank as a guarantor, given the option of choosing an Islamic bank, and does this entail a suspicion of usury (riba), despite rulings from Azhar scholars permitting it?

It is permissible for the seller, in an installment sale, to request a guarantor or a surety to whom he can refer in case the buyer delays payment. The validity of the guarantee contract is a condition for its permissibility in Islamic law. The buyer can emulate the knowledgeable Islamic scholars who have issued fatwas permitting bank guarantees after examining the matter.