script retuns attempt to index nil with Parent?

i am making a feature where if the car touches the water it respawns in a boat

note this script is in the car touch block and it is line 14

local touch_block = script.Parent

local car = script.Parent.Parent
local car_transparency = car.transparency

local respawn_boat_found = touch_block.trigger_respawn
local touch = touch_block.Touched

local boat_name = touch_block.what_boat_is_found

local function respawn(boat)
    touch_block.Orientation = Vector3.new(0, 0, 0)

    boat_name.Value = boat.Parent.Name
    if boat_name.Value == "respawn_point" then
        boat_name.Value = game.Workspace.respawn_points.respawn_point_1
        script.Parent.Parent.properties.can_be_damaged.Value = false
        car_transparency.Value = 1
        touch_block.Size = Vector3.new(1, 1, 1)
        --repeat
            repeat
                wait(0.1)
                car_transparency.Value = car_transparency.Value + 1
            until car_transparency.Value == 1
            repeat
                wait(0.1)
                car_transparency.Value = car_transparency.Value - 1 
            until car_transparency.Value == 0
        --until 
    end
end

local function on_touch(other_part)
    if other_part.name == "boat" then
        print("found a boat")
        respawn_boat_found = true
        respawn()
    else
        warn("did not find boat")
    end
end



touch_block.trigger_script.Changed:Connect(function()
    if touch_block.trigger_script.Value == true then
        repeat
            wait(0.1)
            touch_block.Size = Vector3.new(touch_block.Size.X + 100, touch_block.Size.Y + 100, touch_block.Size.Z + 100)
            touch_block.Touched:Connect(on_touch)
        until respawn_boat_found == true
    end
end)