Could be a million things, where is the noise coming from? Are you sure it isn't just tire or wind noise? And since BMW techs aren't going to drive your car at an illegal 75+mph, I'm sure they are not going to have a direct answer. Also, details on the X5...what year is it?

__________________

An unwavering defender of those I see worth protecting.

"promote the general welfare, not provide the general welfare"

We the People of the United States, in Order to form a more perfect Union, establish Justice, insure domestic Tranquility, provide for the common defence, promote the general Welfare, and secure the Blessings of Liberty to ourselves and our Posterity, do ordain and establish this Constitution for the United States of America.