I needed to replace my wheel well liners because the plastic had become brittle over time. There were cracks appearing at the mounting locations. When I went to install my JTD underpanel, I noticed this problem and I didn't want it flying off on the freeway.

First step is to jack up the car and put the front end on jack stands. I also placed wheel chocks behind the rear wheels. If you need to know how to jack the car up, there are several available resources you will find with a quick search. I have a thread in my sig that explains how to use the jackpad adapter.

Here is the ETK diagram of the wheel well liner.

Part 6 is the rubber seal that is applied to the outside arch of the liner and fits into the fender lip.
Part 5 is the covering piece that spans the gap between the liner, the bumper and the plastic underpanel.

As you can see, in some places part 8 is a plastic threaded insert that is fitted into the body of the car to accept the hex head screws (part 7).

Part 9 is the metal clip that contains the threading for the screws. These go on the liner at the front where it connects to the bumper.

Use an 8mm socket to remove the hex head screws holding the liner in place.

You can see there are two of these screws at the back of the liner. There is also one at the top in the middle.

There is one screw mounted vertically at the inside of the front of the liner.

There are 3 screws on the bottom at the forward edge where the bumper and that covering (part 5 from above) attach. The covering piece (part 5 from above) also snaps into a hole in the liner that you can see between the bumper and the last screw mounting location.

The last connection point is just to the rear of the center of the wheel well on the inside wall of the body of the car. There is a plastic box that holds the attachment points for some sensors. You have to pry the cover open so that you can access the hex nut on the inside.

The liner is on the right and the box is on the left.

Here it is open and you can see the nut.

Here is a closeup of the nut. As you can see my liner broke at this attachment. The correct location for the liner is closest to the body of the car with the sensor box on top of it.

I believe this is also an 8mm socket, but I will have to verify this to be sure.

You may not need to remove the nut completely, but simply to loosen it enough to push the new liner in behind.

As you can see your brake cooling ducts simply rest in the openings in the liner, so it is not necessary to remove them.

Now you want to pop the liner loose of the bumper and start working it loose from the fender.

Do the same at the back and carefully push it upward and inward to get the rubber seal out of the groove of the fender lip.

Once you have pulled it free, it is time to install the new one. It is easiest if you get it started resting in the fender to help support its weight while you install the screws.

Make sure to keep pushing to the outside of the car to keep the rubber seal tightly to the fender.

While you still have some slack, fit the prong in behind the sensor box where the nut is.

You don't want to tighten it into place just yet as you need some slack to make sure it is fitted properly and you can get a good seal between the rubber and the fender. Snap the front back into position as well. Once you have a good seal with the fender, start to install the screws. They go in the same places shown above. Tighten the nut inside the sensor box and then close the lid again. Make sure that the brake ducts fit snugly back into the guides in the wheel well liners. Re-install the screws holding the liner in the front to the bumper and the covering (part 5 from above).

You have now completed the job. Enjoy the shiny black liners while they last.

I bought my liners from Black Forest Parts. bfbmw.com They had the lowest prices when I checked and were willing to ship for a reasonable rate.

The part numbers for the wheel well liners are:
COVERING LEFT 51711977047
COVERING RIGHT 51711977048
(disclaimer: these numbers were for a 97 328is manual in the US)

Thanks for the write-up. :buttrock

This will be handy when I replace mine this weekend.

worked out great, thanks for the writeup :)