On my 512 challenger motor I have 2" TTI headers and 3" pipe into flowmaster 40's that dump just before the rearend. My neighbor complained saying that when I idle my car it vibrates stuff off of his walls in his house 75 feet away. If he wasn't such a jerk I would care but I think he needs to insulate his house better. My other 4 neighbors say they can hear it but it doesn't bother them they love the way it sounds. I haven't been pulled over for it yet but I know I will after all I live in Idaho. In Idaho if it's fun or free it's illegal.