Why act like a frightened Karen?
Walk up to their vehicle with your cell phone camera recording them and ask them why they are stalking you.
If they take off get their license plate number and file a complaint with the police just to get it on record.
If I walked up to you, cell phone recording away and accused you of being a stalker, what would you or most people do? Of course. Drive away. By doing what you’re suggesting the person in the vehicle may themselves have a ccw, become concerned for their life and give you the business end of their weapon. But minimally, most would drive away from someone who may appear unhinged. And then have the police sicced on them.