"Look Mom, a Sandwich!"

 Yesterday on our way to the store I was waiting at a stoplight. All of a sudden Grayson yelled out, "Ohhhh, look mom, there's a sandwich!" And he pointed out the window. He was so excited about this sandwich and started laughing about it. I couldn't see a sandwich anywhere so I kept asking him "Where?" And the more I asked the angrier he got and the more frustrated I became because I just could not see what he was talking about. I looked at all the stores and cars to see if there was a picture of a sandwich on them, and there wasn't. Finally, after some time I looked up in the direction he was pointing (for the umpteenth time) which was hard because he sitting directly behind me, and saw this:

I don't know what it is for, but I laughed so hard! I don't know if it's a sensor of some kind or what it does exactly, but he's got sharp eyes, haha!