Blue Cop Trinity

You were walking along the empty streets of the neighborhood to your home and from behind you heard the sound of a car horn and the screeching of tires. Turning around, you saw three police cars, two of which were driving off to the side, and a Lambordini police car was driving behind you. There was no one in the cabin and it was empty, as was the windshield. You could hear the sounds of an engine, like a purr or something like that.