Winter coats add bulk around your child and prevent a snug car seat harness. Harness straps must be in contact with your child, not a coat. Always strap, then wrap when harnessing Winter Coats and Car Seats: An Unsafe Mix FamilyEducation What should my baby wear when traveling in her car seat BabyCenter How to dress baby in winter: All your options for keeping them warm Today's Parent The Car Seat LadyBest Winter Gear that is Safe in the Car Seat The Car Seat Lady The Car Seat Lady: (most) Coats & Car Seats are NOT a safe combo (here are ways to keep kids WARM & SAFE)