Finally got a chance to install the front flaps, rear I did a couple of months ago. I like these, they are big enough without being obnoxiously big, and offer WAY more coverage than the OEM aero mud guards that Subaru sells (those are a fashion accessory, they barely stick out and down).
He has two designs, these are Flapatax Simplified, bought on ebay for $57.00 including shipping, Pumpkyn (sp?) who is occasionally on the forum makes and sells these.
They install with simple U-nuts and bolts, and are very stiff urethane. I have decals that I might add when it is warm for the rear.
Overall very pleased, at first I got some bum hardware (which is why the rears only were installed) be he corrected that right away, with the correct bolts and U-nuts I put the fronts on in about 20 minutes including putting the car on jackstands and pulling the wheels (and cleaning around the wheel wells):