Tailpipe (DOTM)

Cliffjumper wants to go out and bend some tailpipes. Translation: Tailpipe means embarrassing figurative anatomy.

Also, in Beast Wars, when Rattrap tells Silverbolt to lighten up, he suggest removing a broomstick from the aforementioned part of the anatomy. It is most likely another term for one's exhaust port, or a component thereof.

Classics

Cliffjumper's Classics toy motto says so.

From Teletraan I: The Transformers Wiki, a Wikia wiki.