Where Did the Word Car Come From?

As far as patents go, car always meant railroad car but along about 1904 automobile manufacturers started using "touring car" as a body style description.

That said, Word and Phrase Origins states that "the word car comes from a Celtic word that sounded like karra to Julius Caesar, who gave the name to his chariots. Karra later was Latinized to carra. Surprisingly, the word car appears first around 1300; carriage evolved from it, then horseless carriage, and, finally, back to car again as a shortened form."