You might have to try a different set of pads.
I switched both the X5, from Pagid pads I had installed, and my wife's X3 which just had the brakes done when we bought it so I don't know the brand, for squeaking that I couldn't get rid of, to Power Stop brand and they have both been good ever since. Rotors, driving habits, and other factors can come into play though. Sometimes you can get rid of pad squeak, for a short time at least, by getting them heated up with some panic stops.

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1988 325is (purchased new) sold
2004 X5 3.0 2005 X3 2.5
2008 X5 3.0 (new to me)