Grand Theft Auto: San Andreas has dozens of myths and urban legends from Big Foot to the Serial Killer to a giant serpent living in San Fierro bay. One of the best known myths is that of the ghost car.
In the Back O' Beyond are several wrecked and abandoned vehichles. It is said that if you aproach a certain one of these vehicles, a Glendale, just south of the unnamed lake in the area, at midnight during a thunderstrorm, it will come to life and try to run you down without a driver.
While this obviously isn't true, it isn't entirely false either. The abandoned vehicles were put in the area to give it a more empty and creepy feel. But when placing said Glendale, the programmers goofed by not taking into account the hill under it. When a vehicles spaws, it drops to the ground from a slightly elevated hight, also falling toward the player a little bit. If the player approaches the Glendale from the direction of the second wrecked car just to the west, near the large rock, the Glendale, upon spawning, lands on the top of the hill slope. The game's built in gravety causes the car to slide down the hill toward the player, appearing to try and run them over.
This effect can also be seen with a Vortex boat on a beach slightly northeast of Bayside Marina focused on from the Marina's east most dock. The Vortex will slide down the inclined beach, into the water, and float out a little ways.
So this is true, just not in the way people think.