Is it true that I can use Ford Focus parts to hot-rod my Protegé?
No! The Focus has absolutely nothing in common with the Protegé. Persistent rumors have been floating around the Internet that the Focus is a re-bodied Protegé (or vice versa), or that the Protegé uses a Focus engine. These rumors seem to have been started by some erroneous automotive press reports before the release of the 2001+ 2.0L Protegé. They are totally untrue. The Protegé shares no parts with the Focus, and the 2.0L engine is an F-series Mazda, not a Ford Zetec, so no parts will interchange.
