Can I sue for my airbags not deploying when traveling 50 mph and hitting a tree head on?

Perhaps you can sue. Why didn't the seatbelt lock? That might be a claim. You need to hire an engineer (many thousands of dollars) to inspect your car and test the airbag deployment system to see if it was defective. If it was, then you can sue. However, it sounds as if you would be "watering weeds with champagne." It does not sound like your case is worth enough to justify the expense.

The 1st thing you need to have done is to preserve the vehicle in it's damaged state and have an expert look @ the crash damage, the seat belt, the air bags, the air bag sensors, download data from the EDM and otherwise investigate to see what went wrong. This will cost you thousands of dollars and tie up any vehicle repair, but it is a must if you are thinking of any product liability/breach of warranty case against the auto manufacturer/component part suppliers. You will need a lawyer to pursue such a case, so you should consult local lawyers who regularly handle these type of cases. Be aware that these cases can cost $100,000 or more to pursue in costs and no lawyer will take such a case unless your damages are far in excess of what it will cost to pursue the case.

Get a good trial lawyer and sue the MFG of the vehicle.

Get you good PI lawyer and tell him all the facts: warranty? New item? old item? old car? damaged before? Do you have a doctor who will make the matter causative? Do you have an engineer to prove the malfunction? Are you hurt that bad or just looking for a quick buck?

Yes, you may be able to sue, but I question whether your injuries are severe enough to warrant the cost of pursuing a claim.

Have the matter investigated to see if there was a malfunction. Other than that, I would need all of the details.

You should consult with a good personal injury lawyer who handles product liability cases. In a front-end impact at speeds in excess of 15mph, the air bag should have deployed. If you hit your head hard enough to cause deep gashes, you should also consult with a neuropsychologist as that is the specialty which can test you for potential brain damage. If you notice any changes in your personality or memory, definitely consult with a neuropsych.