Since the 5Zigen center caps I have are just anodized silver, and since 5Zigen doesn't make a chrome center cap, where can I get perhaps either just a plain chrome center cap or one with an Infiniti emblem that'll fit an aftermarket 20in rim?...thanks!

 

There is a M45 at my work with the oem 19" wheels and plain chrome center caps. I would bet the hub size is the same. Talk to a good local tire/wheel place like discount tire.