Have you tried taking the newborn insert out of her car seat? She might have outgrown it. Often they only got to 60cm so might be worth measuring her. May also be reflux as Sophie says. My baby doesn't like lying down if she's not long eaten.
I have a toy dangling from the headrest on the backseat which distracts my little one when he's in the car seat. He has reflux which I've noticed is better while we're out now he's in a buggy with the back adjusted to slightly up from fully flat little bit easier on his tummy. As above also check it you're still using a newborn insert on the car seat it starts to squish them after a while
This is the same for me😩😩😩
My little one has reflux and whilst she still hates the car, changing her pram from the carry cot to the seat fixture has made the world of difference. She's so much more comfortable and happy now she's at a slight incline x
Does she have reflux ? My baby does and hates her pram depending on what mood she’s in and to be honest we use her carrier all the time as it’s easier !!!