John, If the wheel for the E38 has a hole in the center which is 72mm in diameter, and the centering ring on an E39 wheel hub is 74.5 mm in diameter, how can a hub centric ring effectively enlarge the hole of the E38 wheel so that it will fit the E39 hub? Are you referring to wheel spacers or the ring that reduces the center bore to permit fitment on a smaller whel hub?