Multiple Siren Plugin

Allows you to have an unlimited amount of sirens and assign them to SA's default emergency vehicles.
With the help of my other mod called Siren Extender, you can define any vehicle in that mod to be able to use SA's siren system. Then, you can define that same vehicle in this mod so it can have a custom siren.

Everything is editable in a DAT file, which also has further details.