What can be done legally if the airbags didn't deploy when an accident happened?

I had a similar case where the client died and we settled for over a million. I don't know how badly yours son was injured but be thankful he is alive. If he has no injuries, the case has little value. If he sustained long term injuries, there is a chance of settlement, especially if the accident was not his fault which I am not sure I am hearing. To prove the car was defective it needs to be preserved immediately after the accident and saved for examination by a forensic mechanic, who can determine if the failure was all the manufacturer's fault. In summary, if you have injuries, no fault on your son's driving and an expert to testify the car was defective, you may have a case. You will need to have the case looked at by a personal injury/defective products liability attorney.