I have an 06 sport supercharged which has developed a shrill whistling noise which occurs only under accelleration not decelleration, starts @ 64 mph and reaches maximum volume at 76 mph. It quiets down again by 84 mph. Noise has no impact onperformance and is not tied to any rpm range. I've looked for vacuum leaks, low dynamic response fluid levels, belts and have no answers. Ideas??

 

I am assuming that it is not wind related at speed right? I do not own your model and I am not sure but I have seen where the throttle body on other vehicles whistle when you are using other performance items such as a different air intake or something of the sort. You may just need to celan out the intake tube and clean the throttle body intake. In my experience though it has been in more of the rpm range of acceleration.

Just spitballing there so keep looking.

 

It could be the window seals, wipers or something of the sort. I vaguely remember this problem from awhile back. I would suspect a throttle body issue as rob suggested, but since window seals seem to go on the sport and lr3, I would start there. Its cheaper anyways .

 

tape down stuff on the windshield till the noise goes away.

I bet the a pillar panels are loose or the window trim above you is loose.