A guy at work has Jeep mudflaps on his Liberty and I like the way they look. The Liberty is a great candidate for mudflaps since the tires throw all kinds of crap down the side of the Jeep.
I purchased the mudflaps at Jparts.com. They are about $33 a set.
They come with simple instructions (pictures, no words) and all hardware needed.
Theoretically the mudflaps can be installed with the tire on but I took them off for more room.
The first step is to drill out two of the plastic clips.
Insert speed clips where you just removed the plastic clips. This is the hardest part of the installation, and it's not that hard. It just takes a little finger maneuvering.
Set the mudflap in place and put screws through speedclips.
Drill a 3/32" hole through the pre-drilled hole in the mudflap and insert a supplied screw.
Do the same thing for a hole on the underside...
...and the mudflap is installed. Repeat for the other side.
The rear mudflaps are very similar but only have one speed clip. I ran into a slight problem. The supplied speed clip was about a 1/2" short of covering the hole. Not a problem. There's plenty of room to reach behind the inner fenderwell so I modified the speed clip and used it like a nut.
The whole project took less than an hour, including removing/reinstalling the tires and checking the air pressure.