Could just be a legal requirement. Or you could have R33 sun visors?Being a GTR I guess it's always been a manual! I had those ariel switches aswell but they had a picture of an ariel on them.
I've also got some airbag related guff written on my sun visor but I have no airbag! I've got the original 32 wheel and I'm pretty sure 32's never came with airbags.