A lot of people wonder if their car seat is installed tight enough in the vehicle. And you can definitely tell that their car seat is not tight enough. If every time you go around the curve you see the seat belt tilting to the side the baby is Weeeeeee! That's not tight enough, the car seat should basically be an extention of your vehicle. It should be in there so tight that it feels like it's part of the car. The general rule is that the car seat should not move more than 1" from side to side, or front to back after it's installed. Now if you are a petite woman and you are having a really hard time getting them tight enough, what I often do is actually sit in the car seat or put my foot on it, my knee, anything I can to put my full body weight down whil I'm pulling on those tedder straps or on the seatbelt to get it in there very secure. Or ask a big strong man to come help you who get a little bit of a tighter pull. It can be very difficult. One really common mistake however a lot of well meaning parents would think Well, it's not tight enough, adjust the luges or add the seatbelt because If I have both it will be tighter. That is actually completely incorrect. It is not okay to use both the luge and the seat belt when you are installing the car seat and in an accident they could actually work against each other. Always read your car seat instructions manual but you will find no car seats allow you to use the seat belt and the luges at the same time. So choose one and then make sure it doesn't move more than 1" side to side and front to back.