Just whining. The impact driver on low removed the two nuts with no drama.

Now I'm stuck trying to unstick the wiper arm from the wiper unit. I'm surprised because when I was just pulling the arm back, it turned a bit - so figured I might have a too loose problem.

What composite is the center of the plastic arms? I'm thinking it might be a fairly hard rubber insert so that it expands once the nut is tight. Perhaps I'm old fashioned but hoped to see splines which would then just slip off. I squirted in some Kroil so letting it work a bit.