Around 9pm, it was dark and a bit foggy. Vehicle that I am reporting was driving without lights and swerving from one lane to the other. They sped up and cut in front of me, then switched lanes and slowed down and started tailgating me. I flashed my brights to let them know to turn on their lights but all they did was honk and once again, pass me. Before they moved on they flipped me off and sped off.