I also wish there was a rule preventing the use of motor vehicle horns and emergency services siren sounds on any radio station. People are tired driving home and may react unpredictably in dense traffic to sirens and horns on the radio.
Also, I think there should be a law regarding the new electronic billboards, especially at night. They should have a smooth transition over a period of say 10 seconds, instead of instantaneously changing / flashing and distracting drivers.