OK minor accident as we avoided collision with on-coming guy passing in no-passing zone. Guy long-gone, never stopped, no witnesses, so our insurance takes the hit. We had to avoid collision by veering off road and blew out 2 tires and airbags deployed and cracked windshield.

We paid to fix tires and glass, which was less than our deductible, but now the price of airbags is more than car is worth. It's a 100% untouched vehicle otherwise, but high miles and older. No rust no mechanical problems at all.

Question is, is there some rule/law that says we/insurance company have to replace the airbags? Why can't we simply now declare this is a vehicle without airbags (surely pay a higher premium) there are non-airbags cars still on the road from before airbags were invented. They aren't necessary to drive the car. Or does the 'make' of the car necessitate airbags? (I also hear that lots of times airbags are stolen and you never know it until they don't deploy, so plenty of cars have no airbags and are not 'totalled')
problem is, the insurance company says they will pay value of our car to 'total' it less the deductible and then what we already paid to fix the car also comes out (as not being applied to deductible) and then we end up owing them to 'buy' the car back. How can this be?