What is the ruling on dealing with a friend who borrowed from the usurious "LONASAG" to acquire a car on which he works with his brother, knowing that he is stubborn in discussions? Are his funds considered unlawful, and what should be done to convince him?

The described transaction cannot be ruled upon due to a lack of understanding of its nature, specifics, and conditions, as passing judgment on something is contingent upon comprehending it. If it were forbidden, its owner would need to be advised to desist from it. As for the mixing of unlawful (haram (definition)) wealth with lawful (halal (definition)) wealth, it does not render the lawful unlawful. The requested audio files can be obtained from their dedicated section on the website.