Deliberate mistake: At the start of the film when the commentators are explaining the tie situation between the 3 cars the green arrow to the car is out of alignment and misses the car, instead pointing at the track. Pixar Creative Director, Jay Ward, who is this film's team manager (as well as art coordinator) has stated that this was deliberately done as a joke, for fun. It's a little bit off, in the same way that Chick Hicks is a little bit off. This is the video with Jay Ward explaining: https://youtu.be/ZkJre-eC-zE?t=25.
Answer: Instead of sliding on all four tires, he's only sliding on the back two. The front two tires are turned to align with the direction of travel, allowing the car to maintain greater control of the drift. The slow-motion scene when McQueen first accomplishes this shows what's happening.
Phixius ★