| FWIW
the steroe controls on the MFSW are completely isolated from the Cruice controls.
If you fit the MFSW and don't code the BCU then only the stero controls work, this is what I did 1st.
If you then get the BCU coded Cruise works as well, this is what I then did.
If you just want stereo control then you don't need to get the BCU coded. | 
