The front part of the shroud sits on top of the
oil cooler, directing air in seperatetely from the radiator. The rear is mounted to the bottom of the radiator.
The big holes in Nick's pic are for the
oil lines. The duct needs to be trimmed to fit to your body shape on the sides. As does the radiator shround to force all air through the radiator.
It it was any harder to explain I would add a pic... (which I don't have)
In essence: The radiator gets cold air and the
oil cooler gets cold air. Either air flow won't interfere with each unit, nor can it escape to the sides or bottom.