This is not very hard......

Follow these steps and make a drive-by mission.

1. First, make a player with a machine gun.
2. Make an actor who drives the car(friendly).
3. Set the actors route points.
4. Then go Objectives and go to Special player objective then select Teleport to Car.
5. Then select seat "Front Passenger'.
6. Then add some enemy actors at the driver's route point.
7. Finally, play the mission!!