WARNING: This page is about a different car, the 2013 BMW X5, 2012 BMW X5, and 2011 BMW X5. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
(Adapter) For screw-on radiator caps (standard thread)/Series: E28, E30, E31, E32 engine: all, except M51 Free only for motorcycle!!!