The German car manufacturer, BMW has often used this phrase in its marketing efforts. Loosely translated to English, it means "driving pleasure" or perhaps "the joy of driving." This phrase seems to be consistent with their best known marketing catch phrase, "The Ultimate Driving Machine."
BMW: freude am fahren
Typically, a car whore is a man who is insatiable in his desire to own and experience different makes / models of high-line automobiles (e.g., vintage German and Italian marques). A car whore is often working on a limited budget and is an avid do-it-yourself mechanic (i.e., a DIY'er). This individual typically sells or otherwise changes cars over relatively short time intervals (e.g., 6 months - 18 months). When questioned about these behaviors, the car whore may justify it by likening himself to a wine connoisseur in that he is merely sampling various marques and models.
"Dude, you are such a car whore
! How long did you own that 308 GTS Quattrovalvole before you sold it to pick-up that sweet 911S...maybe 6-months?"