What's wrong with this picture?

[superjohn]

Maybe it's got one of those whistle things in it.

Bubba Rubb and his Whistle Tips - Famous Videos

[Porsche Monkey]

+1

Could you imagine riding pregnant dog on that bike with the exhaust blowing right up your ass?

Um, I don't ride pregnant dog. Sounds like your familiar with it though. 

[Big Troubled Bear]

An OCC creation perhaps

[IdZer0]

I saw one like this at my last trackday.

Maybe they try to 'fool' the noise measurment by doing this (as it points the noise more upwards in stead of directly at the measurment device).

It probably won't make a large diference.  But whatever keeps you beneeth the limit. The instructor menioned that if we drive at the other side of the track at the measurment points it could make 1db difference.