For some reason I thought this was impossible, but I have heard of it happening on rare occasions. It just happened to me last night. Nothing unusual about my driving. No new hills or anything. Just a fluke? Apologies for the blur. I was rushing to get the cell phone pic as I was sitting at a stop sign with cars coming up behind me.
No, it's fairly common. Most often you will see this at the bottom of a big hill or in cold weather. Tom