It seems odd  that someone would take as fact that loud pipes save lives ,when research shows that 77% of motorcycle accidents are from frontal crashes and only 3% from bikes that are struck in the rear.  I think that until exhaust pipes start facing forward , I'll be more inclined to rely on defensive driving. Driving like you're invisible ( assuming a car pulling out doesn't see you)  will allow you a longer life than hoping he hears your loud pipe. Who hasn't had a car pull out in front of them?