Have just had a ride in a 4.6 with exhaust mod. Sounded fantastic, the deepest best sounding mod i have heard. You can hear it at idle and inside when stepping on it but when cruising hardly noticeable. Upon looking at it the centre resonator has been left on with two straight pipes coming off it but without the back boxes. The beauty here is that they can easily be bolted on and off without any of the welding issues of the x pipe. i have heard the remus exhaust and it doesnt sound much different from stock. this mod sounds fantastic, hence to say mine is booked in for the same.