I have headers ,, 2 1/2" through flowmasters , quite loud, I was questioned about it when the car was inspected for licensing, I got a pass as the guy was sick of seeing Mustangs coming through Im sure..[just] You cant even fart in your own car and you get a fine in my country...Pfft!
I dont have a radio I just love the sound
just make it so you can fit resonators if it drives you nuts.