My wait for a proper device to protect the rear spring from mud 'n crap is about to be rewarded. MachineartMoto of Frenchtown, New Jersey has asked me to test the prototype of the F800GS MudSling before they commit to their tooling, and they expect to ship final product to the public before the spring riding season.
If you follow the link to the GS Mudsling, you will see that rather than keeping the mud next to the tire like a Hugger, it allows debris to fling free just like the rest of the rear-wheel area of an off-road bike. It shields the spring at the proper distance as a continuation of the BMW's inner fender. One wonders why BMW doesn't offer the solution.
Well, let's keep our fingers crossed, eh? I don't have it yet. Now I'm hoping to ride in some nice wet (i.e., not frozen) mud!