A lot of crazy people on the road.
Last friday an 05 silver mustang GT started pacing me and after I tapped it in 5th gear to keep up with traffic, he shot out in front of me and cut me off, slammed on the brakes, and almost caused the guy behind me to ram into me. All this was in INSANELY heavy traffic, just so some jackass could think he's the man. I know there are horrible drivers out there but they shouldn't be allowed decently quick cars.