Issues with a Tweened Model and Moving Vehicle

So, I’m making a spotlight that moves up and down when it’s clicked. I had the Welds and everything working, then I tried to make it work with a moving vehicle. I have the parts I want to move welded to a part, that is inside a part I do not want to move. When I anchor that part I don’t want to move onto the vehicle, it breaks the tween and won’t animate. Without the anchor, the part won’t move with the vehicle at all. Any solutions?

Tween/Light Script:

local tService = game:GetService("TweenService")
local clickDetector = script.Parent.ClickDetector
local enabled = script.Parent.enabled

local body = script.Parent.body	
local light = script.Parent.light
local emitter = script.Parent.light.SpotLight

enabled.Value = false

local tweenInfo =,Enum.EasingStyle.Linear,Enum.EasingDirection.Out,0,false,0)

local upTween = tService:Create(body,tweenInfo, {CFrame = body.CFrame +,4,0)})
local downTween = tService:Create(body,tweenInfo, {CFrame = body.CFrame +,0,0)})

local function onClicked()
	if enabled.Value == false then
		enabled.Value = true
		print("Scene light enabled.")
		light.Material = Enum.Material.Neon
		emitter.Enabled = true
	elseif enabled.Value == true then
		enabled.Value = false
		print("Scene light disabled.")
		light.Material = Enum.Material.SmoothPlastic
		emitter.Enabled = false


Is there a specialty weld script I need for use with vehicles?

Edit: Now the tween is broken entirely and the model snaps to the ground after launching the game, light will still enable/disable however.