Do all vehicles come with adjustable head restraints?

Not all vehicles come with adjustable head restraints. While many modern vehicles are equipped with adjustable head restraints to enhance passenger safety and comfort, particularly in the context of reducing the risk of whiplash injuries during a rear-end collision, there are still older models and certain types of vehicles that may have fixed head restraints. Fixed head restraints provide some level of support but do not offer the option for adjustment, which allows drivers and passengers to customize their position for optimal protection and comfort. This variability in vehicle design contributes to the answer being false.