51-2191 nut
WARNING: This page is about a different car, the 2013 BMW 550i GT, 2012 BMW 550i GT, 2011 BMW 550i GT, and 2010 BMW 550i GT. However, it is still accessible from the selected car via links, so may be relevant.
0494470 512191 nut Minimum set: Mechanical tools MW
NOTE:
(Knurled nut) Replaced by 00 9 120 (0 490 504) [Released]