There's a few pics on here.
I'm not too sure if these are Jet black, but they do have the performance grills on them.
Figured I might as well post the links:
X1 belonging to member "superbogel":
X1 belonging to member "Twix":
And here's a thread on the black performance grills, though none of the these X1s are black:
http://e84.xbimmers.com/forums/showthread.php?t=767286
Personally, I think it would look good! Definitely not overkill. As long as you either leave your wheels the stock finish or get aftermarket silver/gunmetal finish wheels, it will look sweet.