What's the purpose of the auto tag? It doesn't have a tag wiki or usage guidance, has 8 questions, and seems to be (to me) a site-tag: every question on the site could be tagged with it. I'm of the opinion it's not needed, but if someone else thinks they can edit the usage guidance to make it clear, that would work for me too.
I cleared out auto as ambiguous. I made what I could into automatic-transmission and then deleted the tag from the rest. I then created a tag synonym to point it to automatic-transmission so it won't be used/created again. Yah, that wasn't a very good tag to be using, no doubt. Thanks Cullub for showing it to me.