Traction control pulse brakes the wheel(s) slipping. Since the X5 is all wheel drive and on some year variable I can't think of circumstances where traction control or ABS would wear the rear pads more than front.

ABS stops tires from sliding in milliseconds. Won't learn anything by slamming on the brakes as long as ABS is working properly.

I don't know if front pads on a 2006 3,0 are bigger or not. If they are wear front to back with normal driving will be close to equal.

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X5 4.6 2002 Black Sap, Black interior. 2013 X5M Melbourne Red, Bamboo interior
Dallas