Creaking most likely comes from the strut top hat, they do that with age. Mine went away when when I put newer parts. I don’t think you can swap the top hat on the rear without taking everything apart and the rear suspension is a b*%#€ to do. There are a couple of ways to do it but (at least for me) both are tedious. Look for a DYI on here and see how much you need to take off before you get to it, I’m pretty sure the strut needs to be out all together.
If it’s really faint I’d just roll with it until you have to get in there for other reasons, I don’t think there is any risk leaving it like that, just the damn noise! I’ve learned to stop chasing squeaks and rattles on a 18 year old car
