What is the ruling on purchasing a car through Faisal Islamic Bank, with a deposit held by the bank as collateral, while paying a down payment and the remainder in monthly installments to the bank?

If the bank first purchases the car for itself, taking ownership and responsibility for it, and then sells it to the customer for a known price, even if higher, there is no objection to this transaction. This also applies if the bank stipulates the mortgaging of the car or other assets to secure its right. If "guaranteeing the deposit" means the bank takes a deposit from the buyer as a pledge until the debt is repaid, there is no objection to that either.