Is it possible to use a UV-texture for reflections on an object?
Like say, scratched paint where the base color is blue and the paint has been scratched of so it only reflects on those areas?
I make a UV map where i decide where the scratches (reflections) are and map it to the object.
Thx 
see http://mediawiki.blender.org/index.php/Manual/Using_UV_Textures#Image_Menu.
Although it sounds like you just want to put a alpha 0 slash in your image UV Texture, and the base material or vertex paint or previous UV Texture will show through where the slash is.
Actually it was quite the opposite Map a UV with black scratches, rest transparent, map it to ‘RayMir’ - or you could invert ‘RayMir’ and the opposite happens, thx for pushing me in the right direction !