You can totally hack a car now. I don't know how but the interweb could tell you. I can tell you, I found this video interesting. First off, there should be more than one setting to a car horn other than just ALL OUT DICKHEAD. But there isn't. Second, sometimes we all need to take our foot off the dick pedal and relax. So, relax and watch this.

Now your horn isn't such an obnoxious jerk face.