i got some of my GT-R stuff from this company on ebay. the specialize in items like this. send them and email and ask. they have always be super easy to work with and fast shipping. i got a wallet and a few of the JDM keychains from them. dont see anything Z listed but i bet they can get it if you send them a pic of what your talking about
eBay Store - Ralli Art 3000GT: RALLIART, GT-R, NISMO