Turning? I had NO IDEA!

People who for some reason refuse to use turn signals truly do make life awful. I can't stand when there's barely a cars length of space and they come flying in front of you with no warning. Weaving in and out of traffic as if making some sort of 90 miles an hour wicker basket. You try to give them the flashing hand sign for please use your blinker, you get in front of them using your turn signal so that you can show them how to do and set an example for them, you even flip back and forth between your left and right signal whilst driving in front of them and then give them the what the heck is your problem questioning hand in the air yet they STILL can't seem to get the idea through their heads that maybe they should use their signals. I'm seriously contemplating putting a sign on the hood and trunk of my car saying "Don't be ignorant, use turn signals!" so that people will know why I'm brandishing my double toucans. Please, for the safety and sanity of everybody else on the road as well as you, use your turn signals.