Strut bar install manual attached for reference.
Torque spec on the collared Nuts for the strut bar ends is 35Nm [25.814 foot-pounds] . Two of mine recently cracked[!], reason unknown.
Part number for additional Nuts [each] is 51 717 895 241 - prices vary from $6.00 to $9.00 each [!] you'll need six to do the whole bar.
Part number for Nut Cap is 51 717 896 829 - prices vary around $4.00 each from dealer. Get a few spares!
Most of this info was gleaned from various Ron Stygar posts. He's the MAN. See his post here:
http://www.bimmerfest.com/forums/sho...rut+brace+nuts
regards
rob