Although NASCAR may seem like an every-man-for-himself type of sport, it is in fact a team sport. The most successful drivers all work for multi-car organizations, and crew chiefs and drivers regularly share information with others teams within the organization.
Even on the track, teamwork can play a role. Whether two drivers work together in the draft at a restrictor-plate track or slow up to let a teammate lead a lap, it is commonplace to see two drivers working together and helping each other out.
Granted, friendships tend to go out the window in the closing laps, but that doesn’t mean drivers don’t play favorites.