I haven't seen this posted anywhere, but I got a pretty simple "cut n fit" to work for Rockblokz mud flaps on the rear. The front lined up nicely as stock 5th gen (which was my real problem... 285s rubbing on the mud flaps a little). The rear, I did a little cardboard CAD and figured out I could cut about 4" off the top. I drilled a couple extra holes because my aim was way off and I wanted a little different fit... but really, it was just cut off 4" and drill a couple holes to line up with som existing mounting points.
I kinda like how high they are up in the back. I lost a rear flap offloading when I had a rough departure angle in a spot.