I was going to append this to a thread I stumbled across a couple of weeks ago where there was some debate as to what part was required to avoid:
a) bastardising the OE horn to get at the connector; or
b) cutting off the two pole connector on the bike side for fear of buggering up the can-bus;
but I can't seem to find it again
Well this is it: It's a service part and IS available from your BMW dealer no matter what they might tell you (though you might have to wait a bit for it). The part number is 80 00 0 610 619 and it looks like the pic below. Cost is £9.00. I used it to fit my Stebel Magnum and was a simple case of soldering the two spade connectors to the ends of the wires.
Thus avoids (a) or (b) above and if you're really that tight that you don't want to leave a ten quid horn on your bike when you flog it, it's easy enough to refit the standard item.
Hope this helps someone.
a) bastardising the OE horn to get at the connector; or
b) cutting off the two pole connector on the bike side for fear of buggering up the can-bus;
but I can't seem to find it again

Well this is it: It's a service part and IS available from your BMW dealer no matter what they might tell you (though you might have to wait a bit for it). The part number is 80 00 0 610 619 and it looks like the pic below. Cost is £9.00. I used it to fit my Stebel Magnum and was a simple case of soldering the two spade connectors to the ends of the wires.
Thus avoids (a) or (b) above and if you're really that tight that you don't want to leave a ten quid horn on your bike when you flog it, it's easy enough to refit the standard item.
Hope this helps someone.

I'll wait and see. If anyone else can get hold of one I'll be happy to pay for it.