When a wobble is in a specific range of speed as you describe the first thing I would check is if the wheels are out of balance. Doesn't sound like you have had it done for quite some time. May have thrown a weight. Road force balancing is the best way to go but any decent tire store can get rid of the wobbling if it is a balancing issue.

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