It's been a good few years since I last modded a GTA game. Last one I touched was GTA IV and knew the workings inside and out of replacing car models etc.

 

However, With V's complexity of its file structure and layouts (I.E: police3 being in a totally different location to the others), I am completely lost as to how I can fix the issues on the current model I'm trying to install.

I've managed to replace all police models without issue, however I'm attempting to replace police3 with a California Highway Patrol CVPI (or any car for the matter) but the only models I can find are for the standard police cruiser.

 

I went back to my IV days and simply renamed the file and replaced it, simple no?. Apparently not - The model spawned fine however the lights on the end of the lightbar were.. blocky and when looked at from the front, grey.

I did a quick google search and attempted changing the details of police3 in vehicles.meta thinking it could be an issue with the game attempting to place LED lights on a rotating lightbar, this also didn't fix it.

 

I'm therefore at a loss as to what to do, any help would be appreciated be it in the form of a fix or a model that is actually designed to replace this slot.

The emergency lighting is controlled by a sirensettings value, contained in a carvariations file entry for the vehicle model that also sets possible colors and extras that will spawn naturally on vehicles.

The base game vehicle entries are all contained within an encrypted carvariations file, and can't be directly edited. However, you can add a new entry to any DLC pack's file that will override the original. Check out the "Adding New Emergency Vehicles" thread for info needed for modding emergency vehicles.