Seeing this page I went and ordered the full set of 4 Weathertech mudflaps for my 2008 EL and they arrived. Fitting them was very easy and they fit very well. The rear mud flaps where great they mount using 2 existing screws and have a clip that attaches to the rear wheel arch liner, so nice and solid. The front mud flaps just attach with 2 existing screws (so again no holes required) but I felt the mudflap was not mounted solidly enough for my liking, so I actually drilled a single hole in each front mud flap through to the front wheel arch liner and fitted a reusable plastic clip to make the mounting much more rigid.. So they are hole-less mounting but the front seem poorly mounted to me, so I recommend drilling a hole on the front and adding a third attachment point just to be sure. They fit very well and make a nice addition to the expedition.
Gary