I saw this clip on Youtube a few weeks ago and can’t remember the movie. It was a low budget weird ’70s pseudo documentary on the paranormal or an anthology film? It was grainy looking and in color. The scene was of an older couple(I think) who were in a camper or rv being besieged by large rocks or boulders that were rolling across the desert towards them? I know it sounds ridiculous, but I must know the name of this movie! Can anyone please help me with this?