Warranty should pay for replacement car in this case. I doubt the car would pass vehicle inspection under these circumstances so it may very well be illegal to drive it now.
Ask your insurance too. I don't think they will cover for anything if the airbag failed to work in a crash, if you knew it was failing.
"Enlightenment is man's emergence from his self-imposed nonage. Nonage is the inability to use one's own understanding without another's guidance. This nonage is self-imposed if its cause lies not in lack of understanding but in indecision and lack of courage to use one's own mind without another's guidance. Dare to know! (Sapere aude.) "Have the courage to use your own understanding," is therefore the motto of the enlightenment."