So a while ago, miklo asked me to document how to install the rear mudflaps that come with the Chinese kits from eBay. I finally got around to doing it, so here it is.

The problem:

If you hold the mudflaps up to the rear bumper, you'll notice that they don't quite fit, and none of the holes line up quite right. This is because the rears were meant for this bumper:

Whereas ours look like this:

Now, with a little bit of finessing, these mudflaps will fit okay.

Additional parts to buy:

Screw retainer clips - Available from eBay
Plastic body trim clips - Available from ebay
Vinyl floor tile - I grabbed a sample of a TrafficMaster tile from Home Depot while shopping for flooring

Tools needed:
3/16 inch drill bit
3/8 inch drill bit (Or whatever fits the plastic clips)
Linesman's pliers
Punch/Awl/Screw/Nail/Something to mark holes with.

Step 1:
We need to modify the clips so that they fit the little ridge on the inside of the bumper. If you test fit them, you'll find that the inner 'leg' will hit the inside of the bumper before you get the screw hole centred on the plastic. Take the linesman's pliers, and bend the part with the screw hole like in the picture. Try to get the line that you bend along as perpendicular to the clip as possible. You'll need to do this to 4 of them.

Step 2:
Dry fit the clips and flaps on the bumper. I found that if you line up the top hole 1/4 inch below where the dimple in the bumper is, you get a pretty close fit for the top half. Find a spot near the bottom hole to put the other clip. (Again, nothing will line up right)

Step 3:
It's time to start drilling. You can use the clips as a template to mark where the holes are going to be on both the mudflap and the bumper. Use an clip on the outside of the flap to estimate where the hole is. You'll end up drilling a hole just a bit to the outside of the existing hole. Temporarily attach the flap with a screw.

Step 4:
Now comes the difficult part to drill. Feel around on the lower hole for the clip on the bumper, and use your punch to mark where that is on the mudflap. It's okay if you need to adjust your hole. The head on the screws that come with the mudflaps are nice and big, so you've got some wiggle room.

You might have noticed that the bottom tab of the flap is just kind of hanging there. We're going to need to do something about that. You'll also notice that the bottom half doesn't quite fit. In fact, if we push the tab forward and tuck it above the bumper, it fits a little better. We need to keep the tab forward of where the bumper actually is so that the bottom half sits nice and flush against the bumper

Step 5:
Take your tile sample and cut it in two. I scored the plastic along the bottom, and then snapped it to get a pretty clean break. I taped the two halves together face to face to make sure both sides were mirror images of each other. I drilled two 3/8 inch holes half an inch from the sides to anchor it to the bumper. Now is also a good time ti file down the sharp corners. The hole for the flap itself was basically eyeballed after mocking it up on the car. When drilling the holes, use your smaller drill bit to drill pilot holes so the big one doesn't go wandering all over the bumper. It was here that I found that the tiles might interfere with a bracket, so I filed them down further.

Step 6:
Use one of the clips to secure the tile to the mudflap so you can mock up the position of the flaps, and mark the holes. I ended up having to bend the muflap a little farther that I was hoping to to accommodate the thickness of the tab. Once again, drill pilot holes, then drill your 3/8 inch holes.

Step 7:
Assemble everything with the plastic clips.

The bottom half should go from this:

To this: