First, let's be clear: the optional extra screws need to be used or you have tape holding up on side of each mud guard. As for installation, the fronts are easy. Turn your wheels all the way in one direction and you have plenty of room to drill and install, even with 20 wheels. Turn your wheels the other way and do the other side. Like others have mentioned, pre-drill the 1/8 hole for the optional screw and then when the three factory screws are tight, insert and tighten the optional screw, using the U-clip to hold it tight.For the rear wheels, installation is kind of annoying. You will again need to use the optional screws and need to drill holes in the wheel wells. Rather than pulling the wheels, I used a right-angle attachment for my drill. It was enough to get through the plastic liners. I have the optional wheelhouse liners which creates a two-layer plastic stack and the clip had to go in between, but these mud guards do work with the optional wheelhouse liners. If you only have a standard drill w/o a right angle attachment, plan on pulling the rear wheels.Other than that, there's not much to say. They look fine and appear to be sturdy. Mine only have about 20 miles on them, but I will update this review if they don't hold up.
Rating: [4 of 5 Stars!]