Automobile product liability cases are generally divided into two main types. The first type deals with car accidents caused by a defective auto part. An example of this type of case would be a wheel that comes off when the car is going down the freeway, causing a rollover accident.
The second type of automobile design defect case is the crashworthiness case. These cases address design choices made by the manufacturer that increase the risk of injury to occupants when a crash occurs, or increase the severity of those injuries beyond what would have occurred with a safe design. These cases often base liability on the "second collision" that occurs when occupants of the vehicle are thrown against the dashboard or other interior components of the vehicle. Crashworthiness cases can also be based on an increased risk of fire, or of occupants being ejected from the vehicle in the event of a crash.
The actual cause of the accident itself is generally not relevant in a crashworthiness case. Automobile manufacturers have a legal duty to design a vehicle that is reasonably safe when put to any foreseeable use. Since it is foreseeable that a vehicle may be involved in an accident at some point, the law has developed to require automakers to design vehicles that provide reasonable protection in the event of an accident.
Crashworthy design features include seat belts, front and side airbags, and crumple zones that absorb the impact of a collision. Steering wheel columns that might impale the driver, hard edges on dashboards and other interior components, and unprotected fuel tanks that can easily explode on impact are examples of uncrashworthy designs.
Source: Findlaw, "Car Defects: The Concept of "Crashworthiness," accessed on March 22, 2015