I thiink if you have sport rims they really stand out on silver. 15/20mm spacers and a good coilover kit will just make them stand out even more. But black rims does give the Z a stealthier gangsta look. Just imho and nothing more... I would stay away from the chrome lips though unless I owned gunmetal, black or red. Those colors create more of a positive contrast for the lip vs silver on more bright accenting. Go with a black that's not glossy, because glossy black looks cheap on rims. But don't go matte to the point where they are borderlining gray. But a subtle true black matte finish. Something in the 5 or 6 star design, and extremely dark tint all around as the accent. Also black out the front bumper lower lip or replace it with a thin lipped body kit. Which would look even nicer imho. That's more or less where I was headed with my silver Z eventually.