On vehicles modified for sporting purposes the silencers no longer work because the propagation of sound is different and therefore db-killers are applied or it is avoided to drive them around the city center or during off hours. Then there are people who purposely remove the silencer just to make noise and this also reduce factory performance, these deserve to have their license withdrawn because they take advantage of the fact that noisy vehicles occasionally exist.
because the populist area wouldn’t work and they would move to the more “civilized” area, creating the same problems and still complaining