Houdini Toddler

Kimberly
So my very hard headed , defiant toddler loves to escape his car seat straps. He pushes his chest clip down and removes the straps around his arms but still can't undo the button clip. This terrifies me and I have done everything I can think of to make him stop. I will literally stop my car , holler at him, pop him and a mile down the road hell do it again. Does anyone have any advice or suggestions?