LinearVelocity car can be controlled without a player occupied

I’m making a car powered by LinearVelocity forces, and it works, but even if there is no player in it the car moves.

UIS = game:GetService("UserInputService") --Get Input
local Movement = script.Parent.Parent.Parent.Model:WaitForChild("Red")

UIS.InputBegan:Connect(function(input) --Move Keyboard
	if script.Parent.Torque ~= 0 and script.Parent.Occupant ~= "" then -- I think this has something to do with it but I'm not a professional
		if input.KeyCode == Enum.KeyCode.W then --Forwards
			Movement.LinearVelocityF.Enabled = true
			Movement.LinearVelocityB.Enabled = false
		elseif input.KeyCode == Enum.KeyCode.S then --Backwards
			Movement.LinearVelocityF.Enabled = false
			Movement.LinearVelocityB.Enabled = true
		elseif input.KeyCode == Enum.KeyCode.A then
			Movement.AngularVelocityCCW.Enabled = true
			Movement.AngularVelocityCW.Enabled = false
		elseif input.KeyCode == Enum.KeyCode.D then
			Movement.AngularVelocityCCW.Enabled = false
			Movement.AngularVelocityCW.Enabled = true
		else -- ¯\_(ツ)_/¯ idk the Assistant put this here. It probably does something.
			Movement.LinearVelocityF.Enabled = false
			Movement.LinearVelocityB.Enabled = false
			Movement.AngularVelocityCCW.Enabled = false
			Movement.AngularVelocityCW.Enabled = false
		end
	else
	end
end)

UIS.InputEnded:Connect(function(input)
	if input.KeyCode == Enum.KeyCode.W or input.KeyCode == Enum.KeyCode.S or input.KeyCode == Enum.KeyCode.A or input.KeyCode == Enum.KeyCode.D then --Stop
		Movement.LinearVelocityF.Enabled = false
		Movement.LinearVelocityB.Enabled = false
		Movement.AngularVelocityCCW.Enabled = false
		Movement.AngularVelocityCW.Enabled = false
	end
end)

If a player is either in the car or not, the car still moves.

This is ALWAYS true! It’s either a player object or nil.
It’s not a string!!! You should be checking if it’s nil!!

Simply: if script.Parent.Occupant then...

Quite strange it would be like that, but it worked. Thanks!