In Spanish the Hail Mary starts: "Dios te salve María...".

The word God is in the beginning even though in Latin it isn't, or in English.

A literal translation in English would be: "God hail you Mary...".

It seems it has been like that even before V2, but I find it very strange.

I don't really find it strange. I mean God was hailing her. The angels always spoke for God and the Angel Gabriel said "Hail, full of grace" so God was hailing her.

Here's the  beginning of the Spanish version of the hail holy queen
"God hails you, Queen and Mother of mercy;  our life, sweetness, and hope, God hails you."
This is, from what I know, closer to the original latin than the English version. And also, some Spanish speakers do just say "Ave Maria"