My oil drain plug washer is pretty much disintegrated. I've never once in my life ever replaced or bought one on any car I've owned. But lately I've noticed it will "sweat" a tiny bit of oil around the plug. I want to go ahead and replace it next oil change. Is it worth it to go by a Nissan dealership and buy one there? Or are they completely generic and any one will work (copper preferred I'm sure,as what's on there now)?