Whilst I respect Craig's observations regarding the systems effectiveness , I am surprised the air is taken from the top portion of the radiator cowl. The air flow at that point isn't great ( as illustrated by the video link and the my "dead fly" count after 250 miles). Also to get the best performance an engine prefers cold air - routing the pipe work or intake near the top ie, hottest, part of the rad seems strange to me and I'd think counter-productive somehow. Having said that I haven't tried it so am not talking from experience - just theory.
