That's easy to deal with: They're behind you. Ignore them.
Setting the side mirrors based on the AAA method works for a lot of reasons, and it helps with this too. So does flipping the center mirror over to the dark side.
Out of sight, out of mind.
They can be elect to stay back there behaving however they want, or they can go around be however they need to be somewhere else.
If you just can't stand it anymore, then just hop off the highway. It can be a good opportunity to stop for some coffee or a soda. Or, you know: Just to get out of the car, stretch out the ol' legs, and taste that acrid city air, think about something or someone in the world that is beautiful for you, and chill down a second.
Or just go up one exit ramp and down the entrance ramp on the other side of the crossroad, if the intersection design allows this move to be made safely and conveniently.
They almost certainly won't follow. They'll instead be disappearing down the highway at warp speed the whole time you're doing this, and you'll probably never across them again in your entire life.
It only costs a few minutes. They may seem interminable, but they're few. The benefit is relief from the mounting agony of dealing with this aggressive driver that might otherwise stick with you the rest of the day and that's good for your brain health.
(And if they do follow after you give them every opportunity to not do that? It's not Hollywood or the national news and this actually doesn't happen much in the real world on an individual level, but: Call the police at 911 or 999 or 0118 999 881 999 119 725 3 or whatever it is, and get some help.)
