[ozim]

You either know a lot about designing cars or you know nothing about it.

My guess is you know nothing about it based on malfunctioning airbags that should be possible to be replaced easily.

Airbags are one action components so until they fire up you don’t have certainty. You might check electrical connections or replace them „just in case”. Yes airbags might not be good after 15 years and I don’t think anyone who is driving 15yo car has money or is willing to spend money on replacing them.