請問粵港車牌可否行走全中國，或只限於廣東省？

I don't think so, but it depends. From my knowledge, I know that some cannot go further than GuangDong Province, so you better check it out.

2007-05-29 22:39:16 補充：
I am sure that 粵港車牌 cannot go further than GuangDong Province, however, I am not sure if there are any special ones.

應該可以，因為可能內陸車牌是全國通用的。

絕對可以, 基本上係無限去嘅地方架, 遠至夏門,福建都可以, 因我公司部車都係經常北上.