I used to have a Discovery and the same question popped up on a disco forum, someone went to the dealer and got a quote for £4000 to have the airbags replaced, the car was worth about £2000. The dealer told them that 10 years ago when the cars were new, airbag lifespans where relatively unknown so to cover themselves from insurance claims etc the 10 year service was put in place by most manufacturers. When 10 years had passed they changed their minds after testing them etc, and now don't mention a service life. So basically I wouldn't worry as the cost would most likely write the vehicle off, and the end cause is probably unnecessary (probably due to the fact you won't know until you need to use it! :lol: )