how do i turn this into a killbrick?

Hi. This should work:

while true do
wait(20)
local car = Instance.new("Part", workspace)
local mesh = Instance.new("SpecialMesh", car)
mesh.MeshId = "rbxassetid://1490852609"
mesh.TextureId = "rbxassetid://1490852626"
mesh.Scale = Vector3.new(1.3,1.3,1.3)
--car.Position = script.Parent.Position -- this is not going to work
car.Name = "car"
car.Anchored = false
car.Size = Vector3.new(9,6,20)
car.Velocity = Vector3.new(0,0,-150)
car.Material = Enum.Material.Ice
car.Touched:Connect(function(hit)
	 if game.Players:FindFirstChild(hit.Parent.Name) then
 	 hit.Parent.Humanoid.Health = 0
end
end)
wait(4.5)
car:Destroy()
end