Ghostly pale helping hand

It was a stormy night. A guy was driving in some mountains and his car broke down. He stopped it by a tree and walked down the highway looking for help. A headlight started to approach him from behind. He turned back and noticed a car coming forth very slowly. He walked up to it, opened the door, and sat on the passenger's seat. Then he suddenly notices that there was no driver, but the car was moving!
Before the guy could decide what to do, a sharp turn appeared a few meters before the car and it seemed that the car was going to go off the cliff. The guy trembled in fright, but a pale hand came in from the open window and turned the steering wheel! When the car finished turning around the curve, the hand withdrew. Every time there was a turn, the same hand would come in and guide the wheels of the car to safety.

The guy could not believe all this. As soon as he saw the lights of some rest stop by the road he jumped off the car and ran into a bar, pale, wet, trembling, and telling everybody that he had a most creepy, supernatural experience.

Then two young men dripping in mud came into the bar. One saw the guy and said, "Hey, that's the stupid fellow that got in our car while were pushing."