Great job. But you might have induced a problem. You need to look at your MAF counts. Your MAF should produce a smooth line. I found that blowing directly on the filter caused the MAF to produce a 'spiky' output. The fix is to put a shield over the inlet so that the air flows up and around the filter (I have a similair setup on my 07).
Use of the rubber hose is genius. Even if you have a small constriction, the rubber will produce a smooth transition. Might try and find some pieces for mine.
Add >> Oh! just noticed. Your trim piece you drilled holes in. You did not drill near enough holes for any appreciable air flow. If you take the diameter of all the hoses within 1/2 inch of the tube, and compare to the flow of a 3" I.D tube, you get a true flow picture. It's amazing how restrictive even small hole punched metal is. However, As it appears you shaped the end section (the scoop as you called it), then actually, your pulling air from behind the bumper. That may be a low pressure area due to the design of your front facia, but may negate need for the diffusser. These are all just fine tweaks. Nice job overall!!!
Steeda SRI w/CAI intake. Trubendz SS 2.5" . FR Susp/Struts. Tune by Tom (FocusPower). Rota Grids. SAP rear spoiler. Custom front air dam, rocker panel bits and Rear valance.
Last of the Hatches #28