realoem lists that bolt for $22 or so, which usually means you can find it at dealer for about that cost or online for about 40% less.
Try bmaparts.com bavauto.com and search the 'incolnel' bolt thread...there was a big fight...many just use good grade bolts...not sure how good an idea that is, but in the scheme of things, could be worse!
Upcoming NYC dates: Jan 8 and 27. See Facebook for other shows and PM me if you can make one...love to see you there!
Mangofy your E46!