I bought my used K75 from a guy in Maine who let me test ride it alone for half an hour before I bought it. After I trailered it back to Vermont, I hadn't ridden it for ten minutes when it stopped dead. The L-Jetronic plug was loose. After I set the latch with more tension then reinstalled the plug, everything was ok. Thousands of miles later I found out about that plug mudguard and thought "That might keep the plug secure." Never bought one. Tens of thousands of miles later, I—like BMW—learned the bike doesn't need one. They still can be purchased though. It might be a stylish touch for a queered-out K.