.
If you want to enjoy more zorst music inside your car, then consider aftermarket engine mounts - They'll transfer more sounds but also very minor vibrations.
If you want to keep the Milltek, ask them about getting a shallower back box like mine (they know who RedRobin is) or like VWR's. With less stuffing, it's a deeper sound and slightly louder. Would be very loud indeed with the standard Milltek non-res centre section.
'Mat Ed30' will doubtless be along soon to sing the loudness praises of his Blueflame.
P.S.- 'jhtrophy' is Mat's French bitch