so i just looked Car 3 - Superintendent ● Car 4 - First Deputy Superintendent ● Car 5 - Chief of Patrol ● Car 6 - Deputy Superintendent of Patrol ● Car 13 - possibly Deputy Chief of the Special Functions Division ● Car 41-43 ○ 41=Area Central Deputy Chief ○ 42=Area South Deputy Chief ○ 43=Area North Deputy Chief so i'm guessing Car 8 & Car 45 are in close proximity with the superintendent from what i gathered! for reference to what the heck i'm saying, it's on the Chicago Scanner Guide PDF under callsigns at the very top scroll down to Contents: Chapter 2 go down a bit and under "vocabulary" you'll see Callsigns, click on it and there you go!