Cars are to be fitted with special harmonicas in an attempt to prevent speeding in cities. The devices which only begin to sound when the wind speed beneath the car exceeds 30mph will make it almost impossible to break the speed limit without drawing attention to yourself. The instruments fit neatly under the front bumper of any vehicle and come with a special grill to prevent insects clogging them up. If a driver attempts to tamper with their mouth organ, a saxophone, built into the exhaust will sound. Any driver exceeding 70mph will activate a full orchestra and a recording of Pavarotti singing Wagner which booms out from a speaker hidden beneath the front indicator