Almost every since we have had our 2005 HAC it has aperiodically produce a "slide whistle" sound. That is the best describition that my wife and I can think of. It varies on lenght. One or two notes to several notes.
The "whistle" sound normall goes low to high. The first time it happen by wife was driving and almost panic. It continued on and off for over 30 miles and then just stoped. She drove stright to the car dealer. They checked the car out and could not find anything.
We have been keeping a log. It happens right after the car starts, after it been driven for a while, as we stop, as we start up from a stop, in rain, hot temp, cold temp. The car could "whistle" at least once a week or stop for 4 or 5 weeks.

Has anyone else heard a sound like this?

George M