Mr. Rewrite's summer editing work reinforces another AP style point: One tunes up (v.) a car, provides a tuneup (noun) or is a tuneup (adj.) mechanic.
In no case does AP allow tune-up. But that's how it appears in many, many articles by news organizations claiming to follow AP style. For example:
This appears to be an especially big problem for sports sections, which throw around the term along with countless other cliches.
Perhaps they could use an AP style tuneup.