Consumer Warning:  if you are using a Safety 1st Vantage Child Seat, you need to watch this video made by Dad, Bryan Dussault of Chicago. 

Mr. Dussault documents the looseness of the straps on some samples of the Vantage child seat, and without touching the release for the harness. 

In a car accident, the child may fly through the straps - see the video here - it says it all!