The new X5 has more surface area for the wind to move it around.
My X5 is pretty quiet at 80 MPH. There is some minimal noise at high speeds which probably comes from the large exterior mirrors, all in all it's a quiet vehicle.

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Porsche 996 Turbo (Ruf 550)
Porsche 993 Cab.
Porsche 997 GT3
Audi A8
BMW X5 4.8 White, Black Napa, Sport, Technology, Premium, Prem. Sound, Cold Weather, Rear Climate, Multi-Contour, Sirius, HD Radio, Running Bds., Bamboo