Mostly because it's expensive, it's a lot to invest in 'just' an exhaust.
If you get something that's louder at idle, it will be even louder elsewhere, you won't get a V8 type noise either, their noise is based upon rough running, the V6 is a smooth motor.
However, as civilized as the Motordyne is, the idle noise is 'different' and pleasant.
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'04.5 350Z - Very Motordyne.
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