Is it permissible for a woman to go to Umrah while her Mahram is in the same car, or if he will meet her there?

A woman must be accompanied by a mahram during her Umrah journey, based on the hadith narrated by Ibn Abbas: "No man should be alone with a woman, and no woman should travel except with a mahram." There is no objection to the mahram being with her in the same car or in a second car, as the intent is for him to assist her and look after her during the journey.