This video highlights 2 important installation tips:
On a rear-facing convertible seat, use your stomach to push the car seat into the back of the vehicle seat AND wiggle the car seat side to side WHILE you pull the belt tight. Why wiggle the seat side to side you ask? For the same reason that jackhammers are much more powerful because they move up and down, rather than just pushing down – you will be much more powerful if you wiggle the seat side to side rather than just pushing statically.
Always pull the tail of the belt from “inside” the car seat – not from “outside”
And, if you are installing the car seat in an SUV or minivan and the vehicle seat back can recline… you’ll want to use the seat back recline trick shown in the video below.
Note: While you may not have the same car seat shown in these videos the techniques apply to most car seats.