For those of you that were after a pic of a Silver Z4 with the Black Grills:
Apologies for the dirty car...not the best pics as its pretty grey and overcast in london
The grills were fairly easy to fit...I didnt use any tools and got around the issue of not having enough space for the bottom 2 tabs but pushing the foam cover of the front bar downwards...this gave me ample room to put my fingers into the bottom tabs and release the grill
Once the first one is out the second was fairly easy...again i slide the foam guard slightly down and removed the second...then put the foam guard back in place and put the grill in place