In 2025, when asked why the IIHS doesn't actually perform physical rear-end crash tests, an IIHS spokesperson said that "severe rear-end crashes are relatively rare compared with lower-speed impacts. While these higher-severity crashes do occur, ones that do result in fatalities often involve commercial vehicles and are of a severity that can't be addressed by crash testing." They also cited the government's regulatory requirements, which ensure fuel system integrity, which "to some extent ensures that vehicle structures will hold up in a rear impact." The IIHS also forgoes testing rear-seat head restraints for financial reasons, saying, "We'd be able to evaluate fewer vehicles overall if we expanded testing to other seating positions." The IIHS also recently updated its moderate front overlap crash test and did so by evaluating rear seat occupant protection in addition to front seat occupant protection, so if the tests continue to expand, there's at least an outside chance that rear seat whiplash protection will be tested at some point, too.