I'm noticing a whistling noise at speed while on light throttle, like a high speed wind whistle. I have checked the supercharger but there is no abnormal noise at idle.

It has a new tensioner, idler pulley etc.

Ideas please?

It's a 2005 r53 Automatic

 

Still having the issue? Have you done any work in the vicinity of the intake hoses or air filter box?

 

My car whistles at around 100km/h if the air recirc is set to "on"

It's pretty loud, too. Maybe try adjusting your AC controls next time you hear it.