Sun aura?

I was driving to work this morning and noticed an interesting sun halo, shining through thin cloud, but not a circle, more like an irregular oval. It was bright, hard to look at, and there seemed to be bits of rainbows almost appearing on one side.

And then I realized that the sun wasn't behind that cloud at all, since it was at least 15 degrees left of there. I've never seen this sort of displaced sun halo thing before. Very cool. I don't know if it's a reflection, or the consequence of some odd alignment of clouds, or what. I wished I had a camera with me, and the skill to have the photo come out.