Glossary of Terms: Flutter
WARNING: This page is about a different car, the 2003 Ford Pickup, 2003 Ford F550 Super Duty, 2003 Ford F450 Super Duty, and 2003 Ford Excursion. However, it is still accessible from the selected car via links, so may be relevant.
Mid to high (100-2000 Hz) intermittent sound due to air flow. Similar to a flag flapping in the wind.