Someone in a giant station wagon T-boned me on the passenger side of my 1979 CJ-7 and I rolled three times. Lap belt only but I was wearing it. I remember the impact because it felt like my face was being stretched from the sudden change in direction. The passenger side was hit right at the door, and it bent the body all the way in to the transmission tunnel. Good thing I didn't have a passenger. Only injury to me was bruises where that lap belt held me in the vehicle while the world was spinning around. Without it, the impact would likely have sent me flying out of the Jeep through the flimsy soft top, and then it would have rolled over on top of me. So I think the lap belts helped in that particular crash.