Anything out there that will stop DS undoing his P&T harness?

[MegumiEto]

My DS, 3.6, is an apalling bolter who cannot be trusted not to run away from me or run into the road. At my wits' end with him if he walks anywhere, so he's been strapped into our P&T Sport since DS2 (6mths) arrived.

Last week, he figured out how to undo the 5-point harness and ran off in the supermarket. The day after, he released himself as we were walking along the main road and wriggled out while we were moving.

We've been on house arrest ever since, apart from preschool, as I just can't risk it.

Are there any solutions or products out there that will stop him undoing it in future? Absolutely desperate!

Try a Houdini Stop? Its a simple clip that you put across the front but I have heard people using large food clips or hair clips to hold the harness together elsewhere. If you put it just above the buckle or even two, with one higher up, it may just buy you time to get him back in. I know there is something similar on Amazon but I dont know what its called. Can you do the harness buckle up backwards ie facing him to make things harder?

Do you have reins? Mothercare sell them
Try them and attach them to the D loops on the P&T

You could put him in reins backwards attached to the D rings. He'll only be strapped in at his waist though unless you can rig them up to attach at the shoulders too. And it might be a bit uncomfortable on his back. A Five Point Plus wouldn't stop him from undoing the buckle, but it'll be hard to pull his arms out once he opens the buckle.

Tie his hands behind his back!!! But I'm guessing this could be seen as child abuse so perhaps not the best idea!!!!