Nick, I've had them on my K75S and I think they do more harm than good. If the bike falls over most times it will roll on them and break the indicator. They also tear off the lower bracket with ease and thus offer little protection. They are handy for mounting lamps to though. The only place I have ever been able to find them is on Ebay. I am not sure that K100 ones fit.
The crashbars are rubber mounted to the crashbar mounts. So if you should need a crashbar in the event of a "tumble" they're the first things to break off and fly down the road.