Does the aforementioned divorce take effect after the disagreement in the car, and is the statement included in the condition, "Divorce me if you don't come back, considering you are not my wife," and what expiation is entailed, and is intercourse permissible before performing the expiation?

The majority of scholars hold that swearing by divorce [i.e., using a conditional divorce oath] effects a divorce when the condition upon which the oath was made occurs. This is the established legal opinion (fatwa). Sheikh al-Islam Ibn Taymiyyah, however, held that if swearing by divorce was not intended to effect a divorce but rather to threaten or emphasize, its ruling is that of an oath by Allah, and it necessitates an expiation for an oath (kaffarat yamin). The husband's statement, "you will no longer be under my authority/responsibility" (تبقي مش على ذمتي), is an ambiguous expression (kinayah) that can imply divorce. So, if he intended divorce by it, then it occurs. If the husband is unsure about his intention for divorce, the default principle is that divorce was not intended. Since the wife obeyed her husband, there is no breach of the oath. As for his statement, "and do not speak," nothing results from it as long as he did not intend for it to be included in the oath, for divorce does not occur with doubt.