I can see the logic Rog and Dave of having your inlet filter so placed. The location if I remember correctly is a relative high pressure area once on the move at reasonable speed, as air through cowl hits the upper bulkhead. My only concern would be it's temperature. It would be interesting on a 4 cylinder car to compare IAT with your intake arrangement versus the standard air box fitted with similar minimal restriction filter element, fed by large bore hose with its inlet located above from radiator.
A GDI owner showed me his similar well thought out new installation yesterday. This consisted of a bespoke air deflector fitted within top of cowl, angled upwards to take cool air from well in front of rad and over the top, as suggested by Cain at Wolf Performance. A broad collector located as high as possible behind and slightly behind rad and attached to 4 inch hose hose picked up this cool flow and fed it to air box, mitigating the heat convection/conduction from rad top tank. Important since he had the now common larger aluminium rad limiting space above.
