diff --git a/newmodels_reborn/core/client.lua b/newmodels_reborn/core/client.lua
index db3bc49..4ba33ad 100644
--- a/newmodels_reborn/core/client.lua
+++ b/newmodels_reborn/core/client.lua
@@ -1,13 +1,13 @@
 addEvent("newmodels_reborn:receiveCustomModels", true)
 
-local loadedModels = {}
+loadedModels = {}
 
-local FREE_ID_DELAY = 10000 -- ms
+local FREE_ID_DELAY = 10000    -- ms
 local FREE_ID_DELAY_STEP = 500 -- ms
 local currFreeIdDelay = FREE_ID_DELAY
 
 local function applyElementCustomModel(element)
-    local customModel = tonumber(getElementData(element, CUSTOM_MODEL_DATA_KEY))
+    local customModel = tonumber(getElementData(element, getCustomModelDataKey(element)))
     if not customModel then return end
     local loadedModel = loadedModels[customModel]
     if not loadedModel then return end
@@ -19,7 +19,7 @@ local function applyElementCustomModel(element)
         paintjob = getVehiclePaintjob(element)
     end
 
-    _setElementModel(element, loadedModel.id) 
+    _setElementModel(element, loadedModel.id)
 
     if upgrades then
         for _, v in pairs(upgrades) do
@@ -47,7 +47,7 @@ local function loadCustomModel(customModel, elementToApply)
     if not allocatedModel then return end
 
     local colPath, txdPath, dffPath = customInfo.col, customInfo.txd, customInfo.dff
-    
+
     local col, txd, dff
     if colPath then
         col = engineLoadCOL(colPath)
@@ -58,10 +58,10 @@ local function loadCustomModel(customModel, elementToApply)
     if dffPath then
         dff = engineLoadDFF(dffPath)
     end
-    
+
     if (colPath and not col)
-    or (txdPath and not txd)
-    or (dffPath and not dff) then
+        or (txdPath and not txd)
+        or (dffPath and not dff) then
         if col and isElement(col) then destroyElement(col) end
         if txd and isElement(txd) then destroyElement(txd) end
         if dff and isElement(dff) then destroyElement(dff) end
@@ -70,8 +70,8 @@ local function loadCustomModel(customModel, elementToApply)
     end
 
     if (col and not engineReplaceCOL(col, allocatedModel))
-    or (txd and not engineImportTXD(txd, allocatedModel))
-    or (dff and not engineReplaceModel(dff, allocatedModel)) then
+        or (txd and not engineImportTXD(txd, allocatedModel))
+        or (dff and not engineReplaceModel(dff, allocatedModel)) then
         if col and isElement(col) then destroyElement(col) end
         if txd and isElement(txd) then destroyElement(txd) end
         if dff and isElement(dff) then destroyElement(dff) end
@@ -87,15 +87,16 @@ local function loadCustomModel(customModel, elementToApply)
     elseif customInfo.type == "object" then
         elementTypes = { "object", "pickup" }
     end
-    
+
     -- Set loadedModel info
     loadedModels[customModel] = {
-        id = allocatedModel, baseModel = customInfo.baseModel,
+        id = allocatedModel,
+        baseModel = customInfo.baseModel,
         elementTypes = elementTypes,
         freeAllocatedTimer = nil,
         elements = { txd = txd, dff = dff, col = col }
     }
-    
+
     if isElement(elementToApply) then
         applyElementCustomModel(elementToApply)
     end
@@ -105,7 +106,7 @@ local function countStreamedElementsWithCustomModel(elementTypes, customModel)
     local count = 0
     for _, elementType in pairs(elementTypes) do
         for _, v in pairs(getElementsByType(elementType, root, true)) do
-            if getElementData(v, CUSTOM_MODEL_DATA_KEY) == customModel then
+            if getElementData(v, getCustomModelDataKey(elementType)) == customModel then
                 count = count + 1
             end
         end
@@ -129,10 +130,10 @@ local function freeAllocatedModel(customModel, loadedModel)
         if isElement(loadedModel.elements.col) then destroyElement(loadedModel.elements.col) end
         if isElement(loadedModel.elements.txd) then destroyElement(loadedModel.elements.txd) end
         if isElement(loadedModel.elements.dff) then destroyElement(loadedModel.elements.dff) end
-    
+
         -- Unset loadedModel info
         loadedModels[customModel] = nil
-        
+
         currFreeIdDelay = currFreeIdDelay - FREE_ID_DELAY_STEP
     end, currFreeIdDelay, 1)
 end
@@ -145,19 +146,19 @@ local function freeAllocatedModelIfUnused(customModel)
     end
 end
 
-local function setElementCustomModel(veh)
-    local customModel = getElementData(veh, CUSTOM_MODEL_DATA_KEY)
+local function setElementCustomModel(element)
+    local customModel = getElementData(element, getCustomModelDataKey(element))
     if not customModel then return end
     if not loadedModels[customModel] then
-        loadCustomModel(customModel, veh)
+        loadCustomModel(customModel, element)
     else
-        applyElementCustomModel(veh)
+        applyElementCustomModel(element)
     end
 end
 
 addEventHandler("onClientElementDataChange", root, function(key, prevCustomModel, newCustomModel)
     if not isValidElement(source) then return end
-    if key ~= CUSTOM_MODEL_DATA_KEY then return end
+    if key ~= getCustomModelDataKey(source) then return end
     prevCustomModel = tonumber(prevCustomModel)
 
     -- Get the base model of the previous custom model the element has
@@ -179,7 +180,6 @@ addEventHandler("onClientElementDataChange", root, function(key, prevCustomModel
         setElementCustomModel(source)
     end
     if prevCustomModel then
-
         -- Force-set the base model of the previous custom model if resetting the custom model
         if (not newCustomModel) and prevLoadedModelBaseModel then
             _setElementModel(source, prevLoadedModelBaseModel)
@@ -197,14 +197,14 @@ end)
 
 addEventHandler("onClientElementStreamOut", root, function()
     if not isValidElement(source) then return end
-    local customModel = getElementData(source, CUSTOM_MODEL_DATA_KEY)
+    local customModel = getElementData(source, getCustomModelDataKey(source))
     if not customModel then return end
     freeAllocatedModelIfUnused(customModel)
 end)
 
 addEventHandler("onClientElementDestroy", root, function()
     if not isValidElement(source) then return end
-    local customModel = getElementData(source, CUSTOM_MODEL_DATA_KEY)
+    local customModel = getElementData(source, getCustomModelDataKey(source))
     if not customModel then return end
     freeAllocatedModelIfUnused(customModel)
 end)
@@ -218,3 +218,18 @@ addEventHandler("newmodels_reborn:receiveCustomModels", resourceRoot, function(c
         end
     end
 end, false)
+
+addEventHandler("onClientResourceStop", resourceRoot, function()
+    -- Restore the base models of all elements with custom models
+    for _, elementType in pairs(ELEMENT_TYPES) do
+        for _, v in pairs(getElementsByType(elementType, root, true)) do
+            local model = getElementModel(v)
+            for _, loadedModel in pairs(loadedModels) do
+                if loadedModel.id == model then
+                    setElementModel(v, loadedModel.baseModel)
+                    break
+                end
+            end
+        end
+    end
+end, false)
diff --git a/newmodels_reborn/core/shared.lua b/newmodels_reborn/core/shared.lua
index d3d4bd1..35e0a05 100644
--- a/newmodels_reborn/core/shared.lua
+++ b/newmodels_reborn/core/shared.lua
@@ -1,4 +1,3 @@
-CUSTOM_MODEL_DATA_KEY = "newmodels_simple:customModel"
 ELEMENT_TYPES = { "vehicle", "ped", "player", "object", "pickup" }
 
 customModels = {}
@@ -69,6 +68,11 @@ function isDefaultID(elementType, id)
     return false
 end
 
+-- Variable is unused, it is only necessary for backwards compatibility
+function getCustomModelDataKey(elementOrElementType)
+    return "newmodels_reborn:customModel"
+end
+
 function isValidElement(element)
     local elementType = getElementType(element)
     for _, elementType2 in pairs(ELEMENT_TYPES) do
@@ -123,7 +127,7 @@ local function createElementSafe(elementType, id, ...)
         return false
     end
     if baseModel ~= id then
-        setElementData(element, CUSTOM_MODEL_DATA_KEY, id, not isClientsideScript)
+        setElementData(element, getCustomModelDataKey(elementType), id, not isClientsideScript)
     end
     return element
 end
@@ -181,12 +185,12 @@ function setPickupType(thePickup, theType, id, ammo)
     if theType and theType == 3 then
         local baseModel = getBaseModelIdFromCustomModelId(id)
         if baseModel ~= id then
-            setElementData(thePickup, CUSTOM_MODEL_DATA_KEY, id, not isClientsideScript)
+            setElementData(thePickup, getCustomModelDataKey("pickup"), id, not isClientsideScript)
             return true
         end
     end
 
-    setElementData(thePickup, CUSTOM_MODEL_DATA_KEY, nil, not isClientsideScript)
+    setElementData(thePickup, getCustomModelDataKey("pickup"), nil, not isClientsideScript)
     return _setPickupType(thePickup, theType, id, ammo)
 end
 
@@ -194,7 +198,7 @@ end
 function getElementModel(element)
     assert(isElement(element), "Invalid element passed: " .. tostring(element))
     assert(isValidElement(element), "Invalid element type passed: " .. getElementType(element))
-    return getElementData(element, CUSTOM_MODEL_DATA_KEY) or _getElementModel(element)
+    return getElementData(element, getCustomModelDataKey(element)) or _getElementModel(element)
 end
 
 -- PS. You can't set element model on a pickup
@@ -209,9 +213,9 @@ function setElementModel(element, id)
     end
 
     if baseModel ~= id then
-        setElementData(element, CUSTOM_MODEL_DATA_KEY, id, not isClientsideScript)
+        setElementData(element, getCustomModelDataKey(element), id, not isClientsideScript)
     else
-        setElementData(element, CUSTOM_MODEL_DATA_KEY, nil, not isClientsideScript)
+        setElementData(element, getCustomModelDataKey(element), nil, not isClientsideScript)
     end
 
     return true
diff --git a/newmodels_reborn/meta.xml b/newmodels_reborn/meta.xml
index 4a4d708..1cd5d8f 100644
--- a/newmodels_reborn/meta.xml
+++ b/newmodels_reborn/meta.xml
@@ -5,12 +5,17 @@
       https://nightly.mtasa.com  -->
     <min_mta_version client="1.6.0-9.22505.0" server="1.6.0-9.22505.0"></min_mta_version>
 
-    <!-- Scripts -->
-    <script src="optional/s_testing.lua" type="server"/> <!-- Feel free to delete this script -->
+    <!-- Main Scripts -->
     <script src="core/shared.lua" type="shared"/>
     <script src="core/client.lua" type="client"/>
     <script src="core/server.lua" type="server"/>
 
+    <!-- Testing -->
+    <script src="optional/s_testing.lua" type="server"/>
+
+    <!-- Backwards compatibility with newmodels 3.3.0 -->
+    <script src="optional/shared/*.lua" type="shared"/>
+
     <!-- Exported functions -->
     <export function="isDefaultID" type="shared"/>
     <export function="createObject" type="shared"/>
diff --git a/newmodels_reborn/optional/compatibility/shared/funcs.lua b/newmodels_reborn/optional/compatibility/shared/funcs.lua
new file mode 100644
index 0000000..dff222a
--- /dev/null
+++ b/newmodels_reborn/optional/compatibility/shared/funcs.lua
@@ -0,0 +1,137 @@
+-- Backwards compatibility with newmodels 3.3.0
+
+local OLD_DATA_NAMES = {
+    ped = "skinID",
+    vehicle = "vehicleID",
+    object = "objectID",
+}
+OLD_DATA_NAMES.pickup = OLD_DATA_NAMES.object
+OLD_DATA_NAMES.player = OLD_DATA_NAMES.ped
+
+local OLD_BASE_DATA_NAME = "baseID"
+
+local function convertCustomModelInfoToOldFormat(customModelInfo)
+    local baseModel = customModelInfo.baseModel
+    local customModel = customModelInfo.id
+    local colPath, txdPath, dffPath = customModelInfo.col, customModelInfo.txd, customModelInfo.dff
+    local mod = {
+        id = customModel,
+        base_id = baseModel,
+        name = "",
+        path = { col = colPath, txd = txdPath, dff = dffPath },
+    }
+    mod.paths = mod.path
+    return mod
+end
+
+-- Exported
+function getDataNameFromType(elementType)
+    if type(elementType) == "string" then
+        return OLD_DATA_NAMES[elementType]
+    end
+end
+
+-- Rewrite this function
+function getCustomModelDataKey(elementType)
+    if type(elementType) == "string" then
+        return OLD_DATA_NAMES[elementType]
+    end
+end
+
+-- Exported
+function getBaseModelDataName()
+    return OLD_BASE_DATA_NAME
+end
+
+-- Exported
+function getModDataFromID(id)
+    id = tonumber(id)
+    if not id then return end
+    local customInfo = customModels[id]
+    if not customInfo then return end
+    local mod = convertCustomModelInfoToOldFormat(customInfo)
+    return mod, customInfo.type
+end
+
+-- Exported
+function getModList()
+    local modList = {}
+    for customModel, customInfo in pairs(customModels) do
+        modList[customModel] = convertCustomModelInfoToOldFormat(customInfo)
+    end
+    return modList
+end
+
+-- Exported
+function getBaseModel(element)
+    if not isElement(localPlayer) then
+        return getElementModel(element)
+    else
+        local customModel = tonumber(getElementData(element, getCustomModelDataKey(element)))
+        if customModel then
+            return customModels[customModel] and customModels[customModel].baseModel or nil
+        else
+            return getElementModel(element)
+        end
+    end
+end
+
+-- Exported
+function isCustomModID(id)
+    local mod, modType = getModDataFromID(id)
+    if not mod then return false end
+    return true, mod, modType
+end
+
+-- Exported
+function isRightModType(et, modEt)
+    if et == modEt then
+        return true
+    end
+    if (et == "player" or et == "ped") and (modEt == "player" or modEt == "ped") then
+        return true
+    end
+    if (et == "pickup" or et == "object") and (modEt == "pickup" or modEt == "object") then
+        return true
+    end
+    return false
+end
+
+-- Exported
+function checkModelID(id, elementType)
+    assert(tonumber(id), "Non-number ID passed")
+    assert(
+        (elementType == "ped" or elementType == "player" or elementType == "object" or elementType == "vehicle" or elementType == "pickup"),
+        "Invalid element type passed: " .. tostring(elementType))
+    local dataName = OLD_DATA_NAMES[elementType]
+    assert(dataName, "No data name for element type: " .. tostring(elementType))
+    if elementType == "pickup" then
+        elementType = "object"
+    end
+    local baseModel
+    local isCustom, mod, modType = isCustomModID(id)
+    if isCustom then
+        if not isRightModType(elementType, modType) then
+            return "WRONG_MOD"
+        end
+        if mod then baseModel = mod.base_id end
+    elseif isDefaultID(elementType, id) then
+        baseModel = id
+    else
+        return "INVALID_MODEL"
+    end
+
+    return baseModel, isCustom, dataName, OLD_BASE_DATA_NAME
+end
+
+if isElement(localPlayer) then
+    -- Exported
+    function isClientReady() return true end -- Now the client is always ready :-)
+
+    -- Exported
+    function isModAllocated(id)
+        id = tonumber(id)
+        if not id then return end
+        return loadedModels[id] ~= nil
+    end
+end