Are there different codes when in the police car, like code 2, an code 3 etc... What i mean by code is the different type of lighting. I Already know that you press, Q and SHIFT, and ALT but are there any others?
What minilarro said is true press those buttens on your keyboard and on the back of the lightbar will be diffrent sighns like direction right and left and stop your vehicle but apart from that i am not sure of other types.
Shift :Lights
Q : Sirens
1= turn off sign
2 = emerency (When exiting car it says police checkpoint
3 = pull over (when exiting car it says to stay in the car)
4 = Arrows pointing to the left to divert
5 = arrows poining to the right to divert.
ALT = Bullhorn
C= Pull over/yield/ Alert (Suspicous activity, notify a ped/order a suspect to stop. Notify of green light etc.)