Pan bolts need to be retightened/retorqued.
Find an independent BMW specialist and have them pull the pan. Most likely there is an oil pump mounting bolt laying in the oil pan.
Might as well kill two birds with one stone here because all of the V8's have the bolt come out sooner or later. It could actually be the bolt having worn thru the pan causing the leak. This was mine at 140,000 miles.