Does divorce occur or is expiation obligatory for one who swore by divorce and by what is unlawful that a certain person passed by him and saw his car, then it later became clear that this person was not the one who initially claimed to be "his cousin's son's follower," while he was also referred to as such in previous messages?

The essence of the question is that the swearer intended to lie in his oath by Allah, by Haram, and by divorce, in order to avoid the awkwardness of selling his car to someone other than his friend. What is customarily given fatwa on by us is that divorce occurs when one deliberately lies in it. As for swearing by Haram, it depends on the intention of the swearer: whether it is a divorce, a ẓihār, or an oath. Sheikh al-Islam Ibn Taymiyyah holds the view that divorce does not occur, nor is expiation required, when swearing by divorce falsely. It should be noted that the legitimate oath is by Allah Almighty, whereas swearing by divorce and Haram is among the oaths of the dissolute.