I was going to answer earlier, left bit to see what responses were to this thread. If I was buying a car, I would try to spot any possible faults and depending on that type of fault, decide to buy the car or walk away. If any warning lights show up, I would want to know why and get more information on remedy and cost. The airbag is missing having as you said 'ripped out'! That means to me that it has been deployed unless there has been another reason for it not being in place. We all know that airbags only came in recently so it should not make much differnce in general, but it is a safety feature. What is the history of the car. Was ever involved in an accident? Even before the MOT rules change, I would not have touched the car with that fault. If you do buy a replacement airbag, who ever is going to fit it must disconnect the battery and wait at least 10 minutes touching anything on the circuit. It should left to somebody who knows what their doing. I am not sure about the system resetting itself, but logic tells me that when fitted the light should go out - it did when I changed my leanburn sensor and also a hub when I broke the ABS wheel whilst doing the rear bearing. The bulb trick will not work if the tester is doing his/her job properly, so get the replacement arbag fitted for that MOT. I have said my piece. Konrad