For a couple of weeks now, every time we go somewhere, I'd look back and see Jacinta with her arms out of her seatbelt. I'd tell her to put her arms back in, and she would, then she'd get a thumbs up and we'd be on our way again. This was not unchartered territory since each of my daughters had tried it on for a bit and then given up. After a little while instead of her stopping it, she started refusing to put her arms back in, so I'd go round and do it for her as I had already said I would if she didn't comply.
Then it got so as her arms would be back out again as soon as I'd returned to my seat and she was trying to unclick the whole thing.
I decided I'd need to go out and find a strap to connect the two shoulder straps - which we seem to call a Houdini strap. (In this part of the world we have two shoulder straps connected to another strap at the crotch.) But I remembered something that I'd noticed recently and not had the chance to correct and thought it might make it harder to get out.
I'd noticed on clicking her in that she had recently grown beyond the height of her shoulder straps. There's usually no mucking around where the car's concerned, either we're getting straight in or straight out, so spending 5-10 minutes adjusting the straps hadn't crossed my mind at the key moment.
I moved the straps to the next slot. The next time she was in the car I looked back and she was staying put, not even trying to get out. Every ride since her straps have remained in place. I asked her if the straps were hurting her before. She said 'yes'. Awesome.
Now I'd be lying if I didn't feel a little silly saying that after two previous children I only just worked out that it might be the problem.
So be aware! Shift those shoulder straps! (I'm sure most of you are right on it anyway.)