I guess it's hard to avoid. My child is crazy. He's all torso too I'm hoping to keep him harnessed until 5 but he's already on the last slot so not sure if that's going to work out. I have an evenflo seat that was a third of the price that he can't get out of but that seat sucks in every other way.

I feel like this is something the manufacturer needs to fix , children shouldn't be able to reach a button to loosen there own straps, extremely unsafe.

I dont know how you punish but you could always teach him by "if you do that your getting a spanking(either on the bum or the top of the hand) tell him its unsafe and if you got in a wreck its bad. Just keep saying the spanking thing and he should stop

Ugh my son does this too makes me crazy. He Un clips it or pulls the clip down. I told him the police officers will get mad at mommy so the smart ass now imitates a police sirens when he does it.

Also push the grey clip up to his upper chest

I have the exact same car seat and never had any problems with it. Just pull the grey strap like 5 times.

We have the same car seats and two of my kids do this exact same thing :/

They were tight he pulls the release and bends forward so they loosen. I'm really not impressed with this seat last year I couldn't get him to stop undoing the buckle and now this.

Duct tape his hands to his legs ?

Tighten them up or it might be faulty.