Each Lyft car has a unique pink mustache on the front of their vehicles. Its a cool branding point that serves a functional purpose in helping the rider find the car that is picking you up. Its unique and a smart touch, as I regularly had problems finding the SideCar or Uber that was for me (plain black cars and others blend in).
With any startup in the collaborative consumption space, its important to find ways of making both parties feel comfortable. You’re meeting up with a stranger in an intimate setting where both the driver and the rider may be nervous about who is on the other side. Lyft handles some of this by making it clear that the drivers go through a long background check and approval process. The other thing they do is fist bump.