"The new mechanical wagon with the awful name automobile has come to stay..." New York Times (1897 article)

The New York Times' mention of the name automobile was the first public use of the term by the media and helped to popularize that name for motor vehicles. However the credit for the name automobile goes to a 14th century Italian painter and engineer named Martini. Martini never built an automobile but he did draw plans for a man-powered carriage with four wheels. Martini thought up the name automobile from the Greek word, "auto," (meaning self) and the Latin word, "mobilis," (meaning moving).
The other popular name for an automobile is the car. The word car is derived from Celtic word "carrus," (meaning cart or wagon).

link: inventors.about.com