Okay I modified, dmn_clowns common.shader, and added in a few extra things:
Some of the textures are transparent in GtkRadiant, I find it can make it easier to map when certain textures are slightly transparent.
I implemented the mirror part but I still cant get it to work in OpenArena.
When going through dmn_clowns shader I noticed an Invisible shader, so I created a texture for it, and made it slightly transparent.
The zipped file contains:
maps > test.map
scripts > common.shader
textures > common > editor_images > qer_mirror.tga
textures > common > botclip.tga
Hope its helpful to someone.
*EDIT* I just did some testing and figured out why the mirror wasn't working. We now got mirrors for OpenArena!
Just updated the download link at the bottom. So you can try it all out.
Ow.. and heres a pic of it: