[LEDZEP]

There is some wind noise, and bleed-through traffic noise, but I don't find it all that bad - considering. Once had a Subaru Outback where the mirrors actually whistled at highway speed - now THAT was annoying!

I can definately tell the difference though between the X5's dead silence at any speed and condition versus the X3. But if I look at the difference is seals and insulation, there is no guess work. The X5 was engineered to be very quiet. The X3... less so.