Discription of Events: I was passing a vehicle on I 675 North in my AT&T company vehicle and this person comes up very fast behind me on my bumper. He was very impatient and couldn't wait for me to get over. I finally got over and looked over at the person and called him an ass. He slowed down trying to intimidate me riding by the side of my vehicle. he then finally sped up and exited via exit #3 towards Davenport which happened to be the same exit i was headed. I was not and did not follow him, but i do know that he sped off in another direction. I suppose he figured i was going to report him, and that would be correct. I looked up the license plate via internet search and it turns out that this person is using a plate that does not match the description of his vehicle at all. The plate matches a 2005 cadillac srx and his vehicle was clearly a 2005 suburban or similar type vehicle.