a few reasons

to actually keep the car seat done up while you are not moving.

Yesterday i realized just how important it is to do the car seat up at all times. Whether you are sitting and waiting for someone or in a moving vehicle it is really for baby's best interest to have the seat done up. You just never know when someone might hit you and the car jerks about or hits another car creating double impact.
This happened to a mom and baby i know and luckily baby was not injured but mom has learned that she will never undo the car seat while waiting outside older childs' school again!

I also now do up every safety feature on my stroller or snap 'n go. I used to think there was no need but now that i have really thought about it i think those features are put in place for us to use and are there for a good reason. How sick would i feel if baby fell out of her stroller because i didn't bother doing up her harness while she was in it!