This mod replaces all the sirens (up to/before the Car Shop heist) with the siren from the Bomb Heist: Dockyard.
Installation Instructions
Unpack the files
Copy the "Dockyard Siren" folder
Paste this folder in the "mod_overrides" section in your Payday 2 directory
(example) Steam/steamapps/Common/PAYDAY 2/assets/mod_overrides/paste folder here