Had a weird experience myself about a month ago. I was driving down the road and traffic was mostly bumper to bumper heavy. I looked in my rear view mirror and there was a white Ford Focus behind me . In front of me was a large dark blue car . I glanced at my rear view mirror several times and the same white Ford was behind me and the same blue car in front . As I came to a stoplight I looked at the brake lights of the car in front of me which had been a blue car…and it was now the white Ford that had been behind me. In stunned disbelief I looked in my rear view mirror immediately and now there was a large black truck behind me. No cars had gone around me in the heavy two lane each way traffic and this all happened in a brief time…maybe a minute at most. Very weird.