I asked this question a couple of years ago but didn't get any replies. Maybe one of the new people following the group now will have an idea. :-) I have the Haynes manual for the 850. The car pictured on the cover has much of the bonnet magically erased to reveal the engine compartment. High on the firewall, almost in the centre, is a black, oval shaped device mounted horizontally. It appears to be maybe 15 cm ( 6 in.) long. I can't find any reference to this component anywhere in the book itself. What is it?!? Thanks in advance. cheers, Henry