When model is cloned from replicated storage, it breaks script?

I'm having a very weird problem and it might actually be unsolvable. So in the game i am making, you respawn your car from replicated storage into the workspace. heres the code for that:

local clone = game.ReplicatedStorage.car
backup = clone:Clone() 
function click()
    script.Parent.Visible = false
    clone=backup:clone()
    clone.Parent=game.Workspace
    clone:makeJoints()
    wait(30)
    script.Parent.Text="Spawn Car"
    script.Parent.Visible = true   

end    

script.Parent.MouseButton1Click:Connect(click)

I also have an upgrade system which upgrades the power in the cars. The only problem is that when the car is cloned from replicated storage, the upgrade code doesn't work. However, if i put the car into the workspace to start out with, it does.

heres the code for the upgrade system:

local pad = script.Parent.Parent.Parent.Pad
local debounce = false

while true do
    if not debounce then
        debounce = true
        function padTouched(part)
            if part.Name == "Wheel" then
                local h = part.Parent
                if (h ~= nil)and h.VehicleSeat.EngineSize ~= "2.8" then
                    h.VehicleSeat.EngineSize.Value = "2.8"
                    h.VehicleSeat.MaxSpeedFinal.Value = h.VehicleSeat.MaxSpeedFinal.Value + 40
                    h.EngineBadge.SurfaceGui.TextLabel.Text = "2.8L RACE L4"
                    print "upgrade sucsessful!"
                    wait(1)
                    debounce = false
                end
            end
        end
        pad.Touched:Connect(padTouched)
    end
    wait(0.1)
end

Its very weird.