A.F.
This seems like a no brainer, but I am alarmed at the number of people that I know who do this: It's not ever okay to take your child out of his/her seat while the car is in motion just because they are crying or having a fit. A friend of mine nurses her child in the cargo area of their van while her husband drives. NOT okay.
Great post, J.! I am always a fan of people raising awareness to car seat safety. When I was a new mom, a friend of mine saw my son buckled loosely and she showed me how to properly buckle him. She did it with kindness and I chose not to take it as a slam on my parenting. :) I'm so glad she cared enough to step out and say something. I wish I had read your list when I was a new mommy!