Not sure if this is all car seats but I figured I would post two things...
1. I just remembered I have to change the tilt on the carseat at 3 months. Look at the side of your base and there should be a color/what the color should look like and when you need to change it!
2. Make sure to notice when your baby needs their straps put on the higher level. My daughter is apparently tall for her age and all the sudden she was hating the car seat....i put her in it a week ago and sure enough it was to tight on her shoulders...so I moved them up a level and now she is happy! (it is still safe and snug! Don't do it unless they are still safe!)
Re: Car Seats
Just be sure not to move the shoulder straps too soon! DH moved them a couple of weeks ago and I made him move them back. They should be at shoulder height or just below, not above!
I interpret that as you don't HAVE to change it, but you can for comfort of baby or adult in front of them. It's not necessary.
What one did you get? I was checking some out last night online but there are so many I don't know where to start!
We had a less expensive infant seat and replaced it with a better one after researching more and using it for a couple of weeks.