When it rains, do you use your lights?

[mazdamazda]

Hmm... is there any local legislation for rear fogs?

AFAIK, none.

If there is, all brand new vehicles would be equipped with one.

Only a few vehicles are equipped with OE rear fog lamps... the previous gen Toyota Rav4 (since what we are getting here is the same one that will be sold to Europe), Ford Focus, Nissan X-Trail, etc.