Unrelated to selling the seats as I have them as well but just thought I'd comment that you're spot on as for the torso being a factor in fitting kids back there. My son is short for his age and is about to turn 10. He still has plenty of vertical room in the seats. His cousin was too big for them at 9 but she is a weed with a long torso. The way I tell if they are "too big" for the seats is based on their shoulders in respect to the shoulder straps at the highest setting.