High Noon in 22 seconds.

Although Pulaski is immune to bullets, fire and explosions at the very start of the mission, he still can be killed by running over him with a vehicle.
Since I used the duped GF trick to mark my vehicle, I was limited on the use of OM0 I could use, so I didnt have a call to skip some of the dialogue at the end of the mission.
This could be used if the Explosive Situation trick to mark vehicles is used instead, but the setup would be much longer (if using an unmodded save) as there are a few missions that need to be completed to get from Explosive Situation to High Noon.
Also, I didnt use a replay after killing Pulasking to skip the fade preceding the ending cutscene.