What to do?

While waiting on a red light yesterday, I turn my head to the car sitting alongside us to my left.  There, as bold as brass is a young male driver with a phone to his right ear, chatting away.  The phone was enormous.  His window was open, and his conversation was loud.  It was a busy crossroads junction, so we are sat there for over a minute. There were two males in the car, no more than 18 years old, both of them.  Excuse my language here reader, but he could not give a shit.  He wasn't in any way attempting to disguise his actions, not in the slightest.  In my head, I was seething. 

Would you believe what happened next?

A police car is held at the lights to our right.  Twenty yards away if that.  If the copper just looked to his left, there it was right in front of him.  Just look left, please look left - FOR CHRIST SAKE LOOK LEFT.

He doesn't look left.  We get a green light, and off we go.

What to do?  Bearing in mind, I can't leave the car as my supervisory role insists on my presence - that is a legal point.  Use the horn to get the attention of the police officer?  I don't think you'll find that in the Highway Code.  Shout out the window telling him to get off his phone?  What example is that to give my pupil of handling emotions while driving?

    

Oh man.  Be still my beating heart.  Life is too short.  I only hope that the driver doesn't end up killing someone while chatting away on his phone.