One problem related to air bag not deploy has been reported for the 1997 Audi A8. The most recently reported issues are listed below.
My 1997 Audi A8 has air bag light display in the center of the instrument panel. On a recent visit to the Audi dealership, I was told by the service advisor that they have reset the fault code. Wherever, soon after that the warning light came up again and stay on now. I searched the web and found out there were many owners experienced the same issue on the 1997-2000 model year of the A8. I read the owner's manuel, and it says if the air bag warning is on, when collision occurs, the driver and passenger side frontal air bag will become deactivated (I. E. Frontal air bags would not deploy in the case of a frontal crash. ) since the air bag is a vital safety system, I'd strongly suggest to you to investigate this failure.