my 2 1/2 dd can get out of hers.....she can wrrigle one arm through a strap, then the other. but then she's screaming for help as it's too tight under her arms, lol. i have no idea....we make it good and tight but when she wants to make me stop the car, she can get half her body out. i never drove much longer to see if she could pull herself up and out. i plan to keep her in this seat as long as possible b/c a simple booster would be useless!