Depending on the design of your front bar, normall the guide actually tilts down from your radiator support panel.
The guide will actually scoop air INTO the inlet duct of your car.
You can then use some foam and guide the air into that duct.
BUT, if the duct does look like blocking air getting to the inlet duct, I can include a scoop section on the guide to allow better airflow to the inlet duct.
Send me some photos of your front bar on the SII with the bonnet up, looking at it from the front.