I have grills, gills, hood vents, ///M3 emblem, and the M5 style mirrors in gloss black on my Space Gray E90. I even replaced a pretty rough looking lower mesh grill with a new one i painted gloss black before installing it. I think it's a perfect look against the gray. The E92 is not nearly as difficult to replace the gills. Use the tape technique found in the DIY. I have pics in the cosmetic mods section.
'13 35i M-Sport X3 | JB4 Stage 1 | BMS Intake | H&R Springs | Gloss black grill | CF Wrap and Coded by me | Recaro Child Seats
'15 M3 DCT AW/SO | JB Stage 1 | RKP Diffuser | P3 | M Perf Spoiler | iND Exterior Trim | Recaro Child Seat