That doesn't always work in SC. I passed an unmarked Camaro with blacked out windows two years ago on a two lane road. He was running 45 in a 55. As I passed he sped up with a car coming around a distant curve. I had a choice to slam on brakes or continue accelerating. He clocked me then at 64 as I pulled back in front of him I went to court with a witness and the trooper testified he clocked me with his rear radar at 55 as I passed him. The witness testified he sped up, but I still got a ticket.