How to improve on AlvinBlox's Car spawning tutorial?

So I have watched AlvinBlox's tutorial on Car spawning and it works fine but I have one question

how do I make it where a player can only spawn 1 car then his previous car gets deleted?

All the scripts are in his video about it im to lazy to pull up all the scripts and the hierarchy please help

The general idea is to check if the car exists. There are a few ways you can do this, however, I would recommend doing something like this:

local result, err = pcall(function() -- catches all game-breaking errors
	return car and car.Parent
end)
if result then
	if err == true then
		-- car exists
		car:Destroy()
	else
		-- car does not exist or parent is nil
	end
else
	-- car does not exist or parent is nil
end

-- Car spawn logic

local function onPlayerJoin(player)

	local leaderstats = Instance.new("Folder")
	leaderstats.Name = "leaderstats"
	leaderstats.Parent = player

	local money = Instance.new("IntValue")
	money.Name = "Money"
	money.Value = 22000
	money.Parent = leaderstats
end

game.Players.PlayerAdded:Connect(onPlayerJoin)

game.ReplicatedStorage:WaitForChild("CheckPrice").OnServerInvoke = function(player,NameOfCar)
	return game.ServerStorage.Cars:FindFirstChild(NameOfCar).Price.Value
end

game.ReplicatedStorage:WaitForChild("SpawnCar").OnServerEvent:Connect(function(player,NameOfCar)
	local car = game.ServerStorage.Cars:FindFirstChild(NameOfCar):Clone()
	car:SetPrimaryPartCFrame(player.Character.HumanoidRootPart.CFrame + Vector3.new(0,0,15))
	car.Parent = workspace
	car:MakeJoints()
	car.Name = player.Name.."'s "..NameOfCar
end)