BMW afficionardo's; do you know if the OBC units are interchangeable with
higher spec units, i.e. those which give mpg etc read outs.

I say no, as the sensors wouldnt be pleasant, and I cant see the ECU of this
vintage being able to present fuel data to the OBC.

Friend has the boggo bulb failure / low washer level unit and wonders if he
can swap to a more bells'n'whistles unit.

TIA

Tim..