The odometer on our car often runs backwards.
Stops, then forwards. Stops. Then backwards for a few miles. Etc.
Just once in a while - mostly when I'm driving. And I happen to notice it!!
It has happened when there has been someone in the car who could verify it!! I don't think I was really believed before then.
Don't you just love it when things like this happen?? 
*A* fellow traveler
