First of all great job on the DYOM mod, alot of people love it. But, you are going to put in the save feature in v5 right? just asking.
Seccond, can you give us more space and characters to type for objectives?
Third, on a much easier note, how about immunities? the creators should be able to set the immunities of players and actors.
Finally, you should have the ability to spawn cars befor setting them as an objective in case the player passes that point earlier in the mission.