Read the preview here.Each member has two of six skills, one off the track and one on. For racing, a crew member will be classified as a Blocker, Scout or Drafter. During a race you'll be able to tell your teammate to perform their ability a few times per race (as to not overdo it) and help you get ahead. They're able to win races for you, but you're the main focus so they're present more for support and will drop back to help you out even if it means losing a few positions.
Download the videos here.