You have a few options
First
You buy an English registration plate. It is made of plastic, there is no gouging.
Paste this into some good glue (glue for glass), fill cavities spatula car
Second
You buy Plexiglas, cut to size, you catch it on the screws and glue, spatula fill cavities car
Third
You buy Plexiglas, cut to size, you are doing from the inside mounting. In this way, you plug that you can at any time be removed from the bumper
The ideal option for meetings
In the case of S4 bumper, factory is the cap for the U.S. market
http://img7.imageshack.us/img7/2894/30jnt48.jpg
8D0 807 977 GRU