I was just reading the manual for the Graco TurboBooster, and it said that when the child is not riding in the booster seat, the seat still needs to be fastened down b/c in case of an accident, it would fly around in the cabin and possibly hit and hurt somebody. Does anybody really faster the seat down after the child gets off? I drop my child off at school, and I can't imagine children really unfasten themselves, then turn around and fasten the car seat into the car... I understand the safety issue, but it seems impractical.