The airbox is out of a Mondeo, its roughly 20% bigger in volume and filter area than the MX5 one, took a while searching the wreckers to find something with the inlet / outlet in roughly the right places.
Plan is to fab an adapter bracket for the AFM using a square block of aluminum (which could then easily be substituted for a different one to support a larger AFM, or none at all) , the inlet is going to be a little tricky because its a diagonal oval shape.