Bump.... I just ran into this problem and also am looking or solutions....
Here's the stock BMW bars on the top side. The very top bolt sits on the frame backbone behind the gas tank.
And here's the bottom attachment points. The whole system is ridged which sucks.
If you look close at the top left of the lower skidplate pic, I think you can see the scratch/scuff marks from the previous owner weaseling it in/out. I'm considering getting them out and having a machine shop drill out clearance holes for the filter and drain plug. Argh. STUPID design IMO.