Car seat laws were created for a reason. Not just to make your life more difficult, but to ensure the safety of your little one.
Even so a lot of parents are making the all too common mistake of switching from rear-facing to front way too early. The recommended age is 2 years old before you should switch them around.
The saddening part is most parents know better, but do it anyway. Maybe they think it is safer because they can better keep an eye on and control their baby when they are not facing the opposite direction.
How many of us fall victim to the trait of not speaking up when we know we should? In a case like this, worrying about offending the other person is irrelevant. For the sake of the child’s safety, take a deep breath and tell your sister-in-law (or whoever) that you cannot drive like that with your baby because it is unsafe.
Worrying about if they get angry or whatever is natural, but you need to shame a person who is knowingly doing something unsafe and jeopardizing to their baby’s life. They will feel angry, ashamed and embarrassed. But its one of those, you must do, or you are just at fault for not saying anything.