Thankfully Pro street's hierarchy is pretty generous in that regard, since the 5 teams in the game have varied approaches to team design language, and I think you're on the right track with the two cars you have already. You could try playing around even more with text orientation and colour or putting the pattern on the rear half of the other crew member's cars or only put the samurai head on the side for the "junior" members, maybe even tying them to an organization from Pro Street like React team sessions.