No whistle from my non-aero Thule setups. One has #415 feet (old style) and the other has #450 feet (new style). Thule kayak carrier called Hullavator does not whistle, but with kayak on it I get whistling.
2005 X3 3.0i, CPO, white, auto, adaptive xenon lights, stock suspension, premium pkg, cold weather pkg, heated steering wheel. Self installed: factory hitch, paint protection film, mud flaps