I can see right through the louvres on Molly's bonnet at the Weber, so when it backfires and flames start I will have advanced warning, by maybe 1/2 second.
ALSO photo from a stateside owner showing air flow in and out of the louvres, goes in close to the windscreen! Sorry for poor focus. Regards Peter.

Attached Images
Morgan Louvre air flow.jpg (102.62 KB, 169 downloads)
4/4 2.0 Zetec SSL front and rear