Might be worth having a word with Simon smail at Sitech, reading an article in fast ford about his late S2 he seemed fairly clued up on what does and doesn't work with regards to engine bay cooling on the S2's.
Think some little flaps on the standard air intakes that disrupted the air flow causing an area of low pressure wihch helped draw warm air out of the engine bay work ed better than a raised bonnet IIRC