Suggestion: get four fronts. They mount nicely at all four corners, look
good, function real well, leave room for mud build-up because they don't
mount in the wheel well. I was recently in the San Rafael Swell on very
muddy clay roads and had, literally, mud from the front of the flap
extending forward into the wheel well, almost to the tire. That kind of much
can tear off a regularly mounted mud flap.
example from GoWesty;

http://tinyurl.com/axv8n
That's the right front. That will adapt easily to r/rear; same for l/front
to l/rear.
Just some thoughts/experiences.
bob