bocadillo
Water Gypsy
All horns ought by law to have to make certain sounds like "I'm free" (from John Inman) or "Chase me" (Duncan Norvelle). That'd stop the Neanderthals from using them so much.
Similarly, all air-bags and safety belts should be banned. Instead all steering columns should contain long sharp spears which would aim themsleves through the driver's heart at the slightest collision. Passengers would be seen off by the poisonous gas emitted from the canisters once used to inflate the now-redundant air-bags.
That should see a change to driving habits!