Hey SVTweeter, I want to welcome you to the world of Sound Quality competitions. But, I feel I must mention something to you that you may not like.
If you decide to compete SQ with IASCA, which is the organization I compete in, I would highly recommend entering the Novice class. The Novice class is designed for new competitors, such as yourself, to allow them to learn and grow. In addition, the Novice class uses the IASCA Street format to keep judging simple and understandable for the new competitor. Unfortunately, part of the emphasis on street rules is to maintain the integrity of the OE safety items and controls. In your case, removing the airbag will result in a 5 point deduction for tampering with the safety equipment.
At local shows, those 5 points may or may not make a difference in your placing. However at the bigger shows (if you decide to persue your competition career) it _could_ make a difference. When you get to compete at the Amatuer level after a year in Novice, you can choose whether to compete under the Street rules or Ultimate rules. The Ultimate rules will not dock you points for having removed the airbag.
If you have any other questions about IASCA SQ competitions, please feel free to ask.