The problem with individuals
The problem with individuals with loud exhaust policing themselves is just that, a problem they will not do it. I live in a remote area and the sports bikes and sports cars with modified exhaust race up and down the mountain. The speed limit is 40 but they do well over 80mph sometimes over 100mph. Most have loud and modified engines and exhaust, almos deafening.They pass on corners across double yellow lines endangering fellow drivers and riders. I know requiring the cars to be unmodified will not stop the speeding but maybe with my windows closed I’ll be able to at least hear my radio and TV.