Curious as to the take on the interpretation of the ADR.
http://www.infrastructure.gov.au/roa...Jan2011_v3.pdf
Ref Pages 12 & 13.
Note Figure LH2 shows a rear facing bonnet scoop with a pass noted.
I'd say the ADR is more concerned with pedestian safety.
Any yellow sticker may more than likely be at the uninformed discretion of the officer.
If you wanted to be absolutely certain, you could grab a couple of vent scoops.
SUBARU INDUCTION BONNET VENTS FACE LIFT CARBON FIBRE | eBay