Yelling at people in cars

I have been thinking about how we might go about making our roads more polite and consequently more safe.  I have observed in person and heard plenty more about people who are absolutely enraged on the road.  They insult other drivers, cut people off, and freak out when somebody does something they do not expect.  I think a major factor driving this is simply our inability when driving to say "Sorry."

Considering this I pondered what would happen if we could send messages to other vehicles around us while driving.  Obviously we couldn't let people compose things as they drive because that would be incredibly dangerous and they would mostly spend their time spewing hatred and harassment about.  However, if there was a very limited set of things you could send then I think it might be useful.  For example, if all of the things we could send were:  Sorry, Excuse me, Angry, Hello, Bye, and Thanks I think it would work fine.  We could communicate, people would have a chance to be nice to each other, and when mistakes happen people can wind down more easily if they have received an apology.

What would be even better though is if you could program your car to say whatever you want based on those simple emotions.  If your car said "Apologies guv'na" every time someone sent Sorry it would be a lot more fun.  Especially if other people sending Angry messages it would be hard to get worked up if it came out of your speakers as "Woof, woof" or "I have anger management problems."  Of course there would need to be controls so that cars wouldn't be spammed with messages but I think that would be fairly straightforward to include.  Only accepting a single message from a certain car would be good, except that Sorry would be allowed following another message just in case.

All of this is never going to be implemented of course since driverless cars will be the norm far before this sort of thing ever got up and running.  At that point you can just keep signs saying "BITE ME" in your car and plaster them up against the windows if you really need to express your grievances with other vehicles.  That is, when you bother to take a break from streaming movies *cough* porn *cough* while your vehicle chauffeurs you through the streets filled with other robot cars.