Not really "Fake Cop Pulls Over Real Cop" but, I was driving truck on I-80, across the southern part of Gary Indiana about mid day. Traffic was light and moving well. I was doing 60 (five over on that stretch of road). and passed by an Indiana trooper (in a black, unmarked Camaro with dark tinted windows and chrome wheels, you could only make out the lights from a truck,) who had a four wheeler stopped on the coMedian side breakdown lane. A few minutes later, that cop passed me doing about 80 mph, and strangely enough, had a black Camaro on his back door. Obviously, the black Camaro couldn't see the lights and was trying to impress "someone".
I remember thinking, "this is gonna hurt!" and sure enough, a couple miles down the road, the Copmaro had the Z28 pulled over and was giving the driver a searing ration of shiser. It was a good day.