My cousin was driving in a sports car and a family/economy car was behind us. He was right behind us, about a foot, at all times. We moved to the left for him to pass, and he slowed down. We returned to the center lane, and he sped up. We then sped up 10 miles above the limit to get away from him, he went at least 30 miles faster to get past us, and stick the middle finger at us. We saw him 30 seconds later make a turn. People will tailgate for no purpose. Aside from the 10 miles we went to get ahead of him, we were driving 55, the limit.