Just found this info on a tire/wheel website. I cut and pasted this:


The X6 uses M14x1.5 bolts on a 5x120 PCD but bizarrely has different size centre bores front/rear! The front is 74.0mm and rear 72.5mm

I guess I will have the rears bored out to 74.0mm. There is a "lip" around the edge that seems thicker on the rears than on the fronts. It should be easy to have done.