We were unable to find an Executive Order number for this product. It may be
illegal for use in California on your Nissan 370z. We'd recommend contacting
the manufacturer and asking them for the EO number (if it has one hopefully
stamped on the exhaust unit), or supplying proof of it on documentation
which you can show the smog station. The California AIR resources board
Aftermarket Database is below:
Legal
Add-on or Modified Parts (Executive Orders Database)