I have had wind noise from the day I took delivery of the X3. My 5 series did not have wind noise initially. But with in a month there was wind noise in the 5 series [now fixed/better due to repair by dealer].
I also test drove a 2012 X3. The wind noise is present but is less noticeable compared to the 2011 X3 or rather my X3.
2012 528Xi Black Sapphire Metallic, All Add Ons Except M Sport.
2011 X3 Titanium Silver