destroy sound help

[NickScripter]

I'm using a script that changes the original sound of GTA vehicles. However, I can't destroy the sound when the vehicle is destroyed. Can anybody help me?

Client-side

local sound = {}

addEventHandler("onClientWorldSound", root, function()
    if getElementType(source) == "vehicle" then
        cancelEvent()
    end	
end)

addEventHandler("onClientElementDestroy", getRootElement(), function ()
	if getElementType(source) == "vehicle" and getPedOccupiedVehicle(getLocalPlayer()) == source then
        if isElement(sound[veh]) then
            destroyElement(sound[veh])
        end
	end
end)

function updateEngineSound() 
    local allVehicles = getElementsByType("vehicle") 
    for index, veh in ipairs (allVehicles) do 
        local model = getElementModel(veh) 
        if model == 411 then 
            if getVehicleEngineState(veh) then 
                if isElement(sound[veh]) then 
                    local gear = getVehicleCurrentGear ( veh ) or 1
                    local velocityX, velocityY, velocityZ = getElementVelocity(veh) 
                    local actualspeed = ((velocityX^2 + velocityY^2 + velocityZ^2)^(0.5)) * ((11 - gear) /10)
                    local mph = actualspeed * 70 * 111.847 
                    local minSoundSpeed = 0.15 
                    local soundSpeed = mph/(1000+1000/minSoundSpeed) + minSoundSpeed  
                    setSoundSpeed (sound[veh], soundSpeed) 
                else
                    local x, y, z = getElementPosition(veh)
                    sound[veh] = playSound3D("sounds/engine.wav", x, y, z, true)
					setSoundVolume(sound[veh], 0.2)
                    attachElements(sound[veh], veh)
                end 
            else
                if isElement(sound[veh]) then
                    destroyElement(sound[veh])
                end
            end
        end     
   end 
end 
addEventHandler("onClientPreRender", root, updateEngineSound)