Good point, I'm not certain J'son.
I am certian it will spark many points of view on safety/legalities.
I have taken my GTR over the pits at Dickson twice in the last 6 years and been passed both times without mention. The first time I got the "too loud too low" fail, but with extra tyre pressure and the exhaust swapped over a pass mark. It also passed in Qld with the CF (FPR) bonnet.