I've got no idea on the rules of where you can and can't put a baby seat in a car (i expect i might have to learn within a few years though
)
But you say it can't go in the front because of airbag - god knows why Subaru didn't include a key-switch to disable it like every other car manufacturer out there
Is the passenger airbag on a different fuse to the drivers airbag? Bit of a ghetto fix tho....