My sister has an 8yo ds who refused to sit in his booster so she took him to the store and let him pick his own (blue flame Big Kid!!) and he now sits in it without any arguing. That's awesome and my sister was really excited to show it to me. Then she said "So while I was there I went ahead and got dd a high back." I was like "What?"!! She is 4 next month and about 39 inches and 35 pounds. I told her it wasn't really safe or recommended to have a child that age and size in a booster. Her argument was that her dd wouldn't stay buckled in her car seat, so the booster is actually safer since she does stay buckled. I just can't imagine her wiggly little dd staying still the whole ride. UGH!! I'm not sure what booster it was because I was kind of in shock since I just turned my youngest ds ff a couple months ago. But I looked at how the seat belt fit her and it was great. It wasn't a Turbo, maybe the Evenflo one that isn't the Big Kid high back. Anyway, reassure me that she will be okay. Or not!!