I wonder if anyone can help. MOT is due and the new rules now cover warning lights. My airbag light has been on for the past two years - faulty controller unit was diagnosed after the car was in storage for a couple of years and the light came on when I put on a new battery. Cost new from Audi is Â£480 however they gave me two part numbers for the car. 4BO 959 655 G or the same number ending with an E. They can't tell me which one it is until I remove the old unit and check the part No and it's a bit of a pain to take all the center trim off to get to it just to identify the number. I can get a second hand one on e-bay or around the Â£100 mark. Does anyone know if the two part numbers are interchangeable ? Many thanks.