Problem loading police car .dff, .txd

[HandBuzz]

Hello, I am trying to start a roleplay server but it seem i am not able to do something essential, that being replacing specific police car models and textures. When i go into the game the cars are purely stock, and i can't seem to be able to change them. I tried using pre-built mod-loaders, and building my own script, here it is, sorry for it being so long.

 

function applyPDModels()
    -- tags
    tag4 = engineLoadTXD("copcarla.txd") -- files are in the same folder as the .lua and meta.xml
    engineImportTXD(tag4, 596) -- using the game ids for the car
    tag5 = engineLoadDFF("copcarla.dff")
    engineReplaceModel(tag5, 596)
  
    tag6 = engineLoadTXD("copcarsf.txd")
    engineImportTXD(tag6, 597)
    tag7 = engineLoadDFF("copcarsf.dff")
    engineReplaceModel(tag7, 597)
  
    tag8 = engineLoadTXD("copcarvg.txd")
    engineImportTXD(tag8, 598)
    tag9 = engineLoadDFF("copcarvg.dff")
    engineReplaceModel(tag9, 598)
end

addEvent(applyPDModels, true)
addEventHandler("onClientResourceStart", getResourceRootElement(), applyPDModels)

 So, what should I do? So far my research has led to nothing, because these are the only client side commands that can do the job, but they don't function, please help me.

 

P.S. the files are added in the meta.xml, and also the script.