Mini Bus Racket - Sleeping Dogs
Drop off your first guy in the first stop. On the second stop, take out enemy thugs. Once you get the objective to harass the other bus driver, chase him carefully and honk your horn until the harassment meter fills up.
After the passengers transfer to your bus, enemy vehicles will harass you in return. You don't need to drive fast; use the bus' sturdy body to ram the vehicles until they're all gone. Once done, drop off the passengers to the Night Market stop to complete the mission.