I used Bumper paint. Satin finish (not that the plastic is really going to be "satin".
I've not gotten to the center piece of the rear bumper, the cowl under the windshield, nor the grille.
But here's a question... when do you stop? The latch for the rear hatch is gray, too. But the handles on the doors are not (at least that I can tell). And then do you do the rack? Or is it close enough to black?
I had wanted to do it for a while. I saw Gothamist's, and I personally don't care for the texture of the herculiner (though it is MUCH blacker than the black I used).