Racing stripes typically run from the front of a car, to the rear, passing over the hood, cabin, and the trunk. The stripe (or stripes) may be centered, or off center, and there can be any number of them, although usually you just see one or two. When you see a stripe that runs along the lower edge of a car door, it is not called a racing stripe, instead they are refered to as rocker panel stripes. The stripes you see that run perpendicular to how racing stripes lie, across the rear deck lid, seem to be called bumblebee stripes.
On a more interesting note, I've heard an interesting story as to the origin of racing stripes, I cannot confirm nor deny this story, as I was unable to find any references to it. Evidently racing stripes entered usage in the early 20th century, as the first generation of race car drivers began to face competition from signifigantly younger drivers. The older drivers, who had more influence in the various leagues, had rules put in place that made new drivers apply a stripe to their cars, so as to mark their lack of experience. If a new driver were to prove themselves competent over time, they would be allowed to remove the stripe. Anyone who had a stripe was subject to extra ridicule and criticism. As I mentioned earlier, I have no idea if this is true or not, but it is a cute little story. The person who related it to me used it as a way to bash people with go-faster stripes on their cars, stating that the people who put such stripes on were emulating the "bad drivers", and that they were a sign of cluelessness.