What is the ruling on someone who quarreled with another in a car over the radio, with one wishing to recite the evening adhkar while the other wanted to listen, and the latter then insulted the former; and how should one deal with him?

If a person curses the adhkar (remembrances of Allah), then this act is disbelief, because Allah says: "And if you ask them, they will surely say, 'We were only indulging in idle talk and play.' Say, 'Is it in Allah and His verses and His Messenger that you were mocking?' Make no excuse; you have disbelieved after your belief." Mocking any matter of religion is disbelief, and cursing is more severe than mocking. This was affirmed by Ibn Taymiyyah and Ibn Baz. This person must be advised to repent and warned about the consequences of his words, for the Prophet, peace and blessings be upon him, said: "Indeed, a servant may utter a word that displeases Allah, to which he pays no attention, yet it causes him to fall into Hellfire."