Yeah it was a bit of a pain to remove but i did it after much jiggin about with the screw driver!
and no you cant buy a black surround, i tried but theres no part number for it, the grille comes complete including the surround and audi rings.
The normal grilles have a built in number plate holder aswell but the S line ones come with a seperate piece. I think its so you can change the plate for different country spec sizes.