Issues with 3 yo and Britax Renaissance straps

[elvislives]

3 yo DD is in a Britax Renaissance seat. She's only 16kg so not yet too big, but we are having an issue with the straps.

She has started to take her arms out of the straps while I'm driving. Unfortunately we have a 30 minute commute along single carriageway roads where there is nowhere to stop, so I generally only notice when we arrive. She gets a lecture about being dangerous but just does it again.

I always tighten the straps as much as they will go. There doesn't seem to be a way to make the crotch strap any longer. Tightening the straps seems to be pinching her legs on top and underneath, but doesn't stop her getting her arms out.

I know the fastening needs to be on the bony part of her pelvis but I feel it could come up a bit.

try zipping a body warmer/buttoning a cardi over the straps once there fastened.

Thanks but that won't work- she can undo anything.

I was hoping somebody could advise me on the straps.

the in car safety centre had clips but not sure what seats they are for iykwim. call them and see what they advise.

uk law is that only 1 safety clip should need releasing to free the child, in the usa 2 safety clips are standard on many seats.