Is it permissible for a car dealer to fill out a bank form for a customer who is buying a car with an interest-based loan? Does that count as cooperation in sin? Does the ruling on uncovered credit cards fall under this? Is it permissible for the dealer to withdraw the car amount via an ATM, knowing that the customer will pay with interest?

It is impermissible to fill out a form for a usurious transaction, as it falls under cooperation in sin, based on the Almighty's saying: "And cooperate in righteousness and piety, but do not cooperate in sin and aggression." As for withdrawing the price of a car using an uncovered Visa card, if the right can be obtained through other means, that is preferred. However, if there is no other way to obtain the right except by withdrawing from such cards, and not dealing with their owners would lead to hardship and difficulty, then there is no harm in doing so due to the principle that hardship brings ease, especially in lands of disbelief where the rulings of Sharia are not upheld and dealing with these cards is prevalent.