I know for a fact that in the US, there is no law saying that you must have an air bag, I'm not sure about california specifically, but it's considered to be a luxury, not a mandated law, seat belts are a different story. Any way, another thing you may want to consider, is that if you insurance company finds out you were in an accident, does an inspection, and finds out you don't have an airbag and never told them about it, they have reason to drop you, and not pay for your accident, and for an extra 20% increase in insurance to not have an airbag, it's not worth it. Think about that one....

Later,
Aj