Not woo, but very odd story from me.
We were driving in France in late winter. We'd had a delayed crossing and it was about 5.30pm, already dark. Hubby, DD (aged 3) and I in the car. We pulled into a rest stop off of the main road, small building with toilets and awful lighting, but all we needed to do was change the DVD in the back and then carry on, didn't even need to get out of the car. No-one else and no vehicles in sight. As hubby puts the handbrake on there is a knock at the drivers window (note we are in a French make of car, and the knock was at the UK driver side) I jumped, hubby jumped and a Gendarme appeared at the window. He motioned to wind the window down, which we did and in French, explained that we had to move immediately, that the area was crawling with thieves and they were targeting UK vehicles. With that, he disappeared, literally vanished into the darkness. There was nowhere obvious for him to go, only a toilet block. We locked the doors, put the headlights on full beam and looked around, but couldn't see him anywhere or any vehicle. Oh, and the other weird thing is that I never studied French, have only a basic understanding of German and Spanish, yet understood everything single word he said, hubby who took French GCSE got about one word in five!