The designs of seats and head restraints in 21 current SUV, pickup, and minivan models are rated good for protecting people in rear impacts, but those in 54 other models are rated marginal or poor. Another 12 are rated acceptable. The latest evaluations of occupant protection in rear-end collisions by the Insurance Institute for Highway Safety found that the seat/head restraints in more than half of light truck and minivan models fall short of state-of-the-art protection from neck injury or whiplash. The ratings of good, acceptable, marginal, or poor for 87 current models are based on geometric measurements of head restraints and simulated crashes that together assess how well people of different sizes would be protected in a typical rear crash. Read more about which cars performed the best and worst.