Two young men in a silver european make vehicle (BMW?), Colorado license plate number 743 RJZ. The passnger threw soda cup half full out the window at the mail boxes located here:
Then they continued and threw another cup at the mailboxes located on the right somewhere in here:
I followed them to have a talk with them or their parents but they noticed I was following and speed away exceed the speed limit by at least 20 mph in a residential neighborhood (no, I did not pursue).