As new condition, it was on my ND for about 20 minutes and had exhaust flowing through it for about 5 minutes, enough that I decided it wasn't loud enough for my taste.
The Roadstersport Race went back on my car.
Openflash has it on sale for $699 plus shipping, I'm asking $600 plus shipping.
I have the original box and packing if it needs to be shipped.
The diffuser is included and was not installed on my car.
The bolts and screws are still in their plastic bag taped to the underside of the diffuser.
Fits all ND Miatas.
Picture from the Openflash store.