I had a reasonably priced digital replacement for my sender from Clipper some years ago which was compatible with the existing fuel gauge on my 2006 B37. However, when the gauge rusted (yes, thanks Bavaria for supplying an iron-based unit) and I tried to source a replacement from ASAP supplies I was told that the units are indeed specific for Bavaria and that they could not provide one. I have since sourced a replacement gauge at a comparable market price from Clipper.