Seat belts can fail due to poor design and poor manufacturing. Common seatbelt issues include false latching, inertial unlatching, weakened webbing, and retractor failure, for example. Defective seat belts can cause devastating injuries, as they can fail to work properly in accidents. If you suspect that the seat belts in your car are defective, it is essential that you take your vehicle in for repairs as soon as possible. If there is no solution, stop driving the unsafe vehicle and file a lemon law claim immediately.