Im gonna shop around for OEM S4 door moldings and side skirts to install on my car, i currently have the V fiber RS4 knock off side skirts. They ARE fiberglass, but professionally prepped and painted by Premier auto body here in Elk Grove CA. http://www.premierautobodyofelkgrove.com/index.html Im gonna ask $250 for these locally, and $300 shipped. They do have some slight scratching on the bottom of them from hard turning, but they aren't noticable and the paint hasn't been affected by it. Let me know if you want em. They will match any silver A4 perfectly, i also have documentation of the paint work if you want to see it upon pick up.
Note: if you install these on your car you will have to modify the stock door moldings or make custom ones like i have in the pic below.

Here is a pic of it on the car.





And a pic of the custom molding premier installed on my car, you can also use S4 moldings, the A4 ones hang over the side skirt, which obviously would look stupid.