Working emergency lights and siren

[Adeor]

I am planning new MOCs and two of these are police vehicle and fire truck. I want both of them to have working emergency lights and siren. For the police vehicle, I want three siren modes: "woop woop", scrambler and avail. 

My question is how do I pull this off and can I do this using PF lights and BuWizz battery?

[Zerobricks]

You could use the old 9V components, the sirens have 2 types of ringing according to the polarity. You can connect the siren via 8886 PF extension cable and a 9V cable. For lights, the old 9V system also had flashing lights. Or you can use PF/PU lights, but to there is no support for blinking in the BuWizz app... Yet