Road tandem with SKS Racer blades does the trick when mother nature doesn't cooperate. No where near as good as having full-coverage mud guards, but better than nothing... at least if you're riding alone. Of course, being the only one with mud guards on a group ride only works if you're willing to pull the entire time. On the up side, we find that just having them in the truck seems to keep the rain away (Murphy's Law, don't you know).
Off-road tandem with quick-release SKS something-or-others. The front guard is exceptional, the rear adequate but can be more trouble than it's worth once it starts to collect mud and gain weight. Also, the attitude of the rear mud guard changes from 9 O'Clock to about 11 O'Clock once you bottom out the rear shock and drive it into the rear tire and looks really weird... kinda like a bird's tail sticking up while they grunt one out.