Trailer

Hi all, I’m trying to make an animation for a project involving this trailer model. It’s been a while since I’ve been in Blender, and I’m just trying to get a clean simple look for this, nothing showy. I’m mostly satisfied with what I have except for the strange square shapes near the foreground of this image. I know this is caused by ambient occlusion because when I turn it off, the squares go away. Anyone have any ideas what could be causing this?