Ai Script Manager - Offset Delay / Start Delay explained more in detail.
2Not seen here is you can also turn on slow motion when recording your videos to drive better when needed. And it will play back at regular speed.
I forgot to cut the part with the two pickup trucks. Well better you see things don't always work.
*Offset delay = How many sec in the future or head start a cars recording plays back at.
*Start delay = How late in sec a cars recorded playback will start.
--You can pick in the AI manager the car you want to be controlling when the playback starts to avoid fumbling between cars. That can be a hassle when there are many cars. If you want to tab between multiple cop cars I would suggest spawning them one after the other so that you can select the one thats first, then tab to the others to set all the sirens.
---One thing I did not try was to pause the sim while recording and tab between cars to see if it will but you can turn on slow motion for sure up to 100 times to allow plenty of The Flash speed to tab between cars to turn on their light bars if it does not work paused. Then simply take the advantage of the slow motion to free cam over to where the action will be recorded and set time back to real time or record it at a slower motion assuming the video card is recording the desktop. It records what it sees in my case using Alt -F9 with my NVidias screen record function.