When someone is flashing their lights at the car in front of them it is because the jerk, using the brothers’ word, driving too slow in the fast lane who does not realize he is the jerk that is the problem by driving slow in the fast lane.
The proper thing to do when you get the flashed high beams, or you are passed on the right, is to move a lane to the right or speed up till the high beams stop getting flashed or you stop getting passed on the right. Yes, you need to do this safely, because no on whants a Darwin Award for their actions.