>>28517526Because most of modern cars have too much sound deadening mats between engine bay and interior. This makes it difficult to hear the engine from idle to middle rpm. Its easier to just modify exhaust system to be louder than taking front interior apart to reduce amount of sound deadening mats.
I personally kept the stock exhaust because I dont wake up everybody at mile distance during my night time driving times. Also I dont want it to be too easy for cops to hear from longer distance when I'm speeding with my car.