Hey, they're kids, not refrigerators. Pay $200 for a high-end car seat and you don't expect an extra Ring Ding at lunch to snap the straps. All the same, the Children's Hospital of Philadelphia found that properly used, the current range of safety seats "accommodates a broad spectrum of children's body sizes, including children with higher weights." That will surely come as a relief to parents who worried they'd have to FedEx the chubby ones ahead.