1) You (or your passenger) can submit a claim to the other driver's inurance and they may cover it, but bear in mind they do not have to do so unless you were to sue their driver and win. Only a successful lawsuit compels the other side and/or their insurer to pay; payments or settlements made without a court judgment in your favor are voluntary. The insurer may choose to pay if deems paying more cost effective than refusing to pay, then potentially having to defend their driver against a lawsuit and possibly losing and then having to pay anyway. Or if they deem your case weak or that you are unlikely to actually sue, they may very well refuse to offer anything.2) You can sue the other driver if he was at fault, as appears to be the case based on what you write.3) You can potentially sue the rental car copany and/or car company if the seat belt and/or air bag was defectively designed, manufactured, or maintained and that contributed to your injuries. Bear in mind that such a product liability lawsuit will require hiring a seat belt or airbag expert (such as an engineer who designs them or investigates their failure) to prove the defect, etc.