How do you position a non-moving vehicle in an EDSMAC/EDSMAC4 event without getting an "Event Termination: No Vehicle Velocities Assigned," message when you try to execute the event?

The key to answering this question is that you must do exactly what the message is asking you to do: You must assign a velocity to the non-moving vehicle. Since we want this to be a non-moving vehicle, all we have to do is assign the vehicles velocity to be zero (0). Then when you execute the event, the vehicle will stay put just as you assigned.