This is a car built to last 6-7 years that has lasted 13 years. Airbags suddenly going off in old cars is not actually very common, but all airbag warning lights are now subject to the MoT test and a car will fail if the lights show anything wrong. If the problem isn’t something simple like an external cable or connector, it will make many cars like yours economic write-offs. www.airbagman.co.uk may be able to help.