To disable the airbag system on an FC you just remove the control box and battery pack under the dash. They're blazing teal boxes with Ford logos on them. Is it much different in the FD?

 

The airbag resistor does not need to be fit into the hub, but rather can be incorporated into the SRS harness in dash under right knee; this circuit solely goes to wheel is it leaves pass SRS intact. Search under hubs and my name. I used the Momo collapsible hub adapter along with NRG low profile QR on a Sparco wheel, horn button even works. This is not rocket science search the web for Miata installs, with so many Spec Miata’s every solution has been tried.