It is needed to build some special parts for a project like this.
First up is an adapter for the prop shaft. I use a Volvo 740 drive shaft which I extended 8cm. I turned the drive shaft back and front, then it´s fits directly on my Opel Omega 3000 diff, but to get it to fit on the BMW gearbox needed an adapter.
The next part of the build is to get to the drive shafts back, those are the Omega 3000 diff is the strongest available to Opel but they do not fit straight off. The drive shafts are of great inner and outer flange and the original Clibran it's small outer flange.
To solve this, bought two outer flange of Opel Omega 2.4, they fit the drive shafts and they fit in the Calibration hubs. But 3000 diff is a bit wider than the original diff so I shortened the 2.4 outer flange 5mm.