My three-year-old is in a booster seat, and I don’t even know how this happened. Basically, I blinked, and now he’s a walking-talking-functional human being with independent thoughts and ideas. I’ve mentioned how buying clothes for him is a little weird because he’s huge for his age. The car seat situation is the same. He’s too big for most harness seats, but he’s still mentally immature and needing something SOLID that keeps him contained in one spot if he wiggles a bit. With our frequent travels, we also need something that can go from car-to-train-to-Uber without much fanfare.