My son is badgering me to take the back off his high back booster seat as all his friends have. He is 7 and 134cm tall. I understood the recommendation is that these seats are used up until the age of 12. Is this recommendation for just the booster seat bit and not the high back bit? I thought the high back bit is used to help if there was any side impact to stop child's head from being too bashed around. My son is right almost all the parents I know have taken the backs off. I'm in a dilemma. What would do you do or have you done?