STREETSOFFIRE the part # 51710305705 is for the X3
DOCMIKE the runnigboards come with wheel flairs. the wheel flairs that arent compatable are in the accessories catalog on page 6 letter f and are pictured on page 7. if you dont have a copy of the book here is a link to a pdf file of it
http://www.xoutpost.com/pdf/BMW%20X5%...%20Catalog.pdf