Well, no. 'Pulp Fiction' doesn't show any instance of cars being permitted in restaurants. Restaurants are places for people to eat and socialize, and having cars in them would disrupt the normal flow and function of the establishment. Plus, it would be a safety hazard. So, clearly, cars are not allowed in restaurants in 'Pulp Fiction'.
I don't know who created the 'cave full of cars story' as there is no information given. It could be an unknown local storyteller in a community where the cave exists, or it could be a writer who made it up for a book or a short story collection.
I'm not sure specifically what the 'cave full of cars story' is about as it could be many different things. It might be a story about a cave that has been filled with cars for some strange or interesting reason, like perhaps a collector who stored all his cars in a cave, or it could be a fictional story where cars end up in a cave in a post - apocalyptic world.
The 'barn full of cars story' might be related to a collection of cars stored in a barn. Maybe it's a story of a person who had a passion for cars and over time filled a barn with all kinds of automobiles. It could also involve the discovery of the barn by someone else, like a collector looking for rare cars and stumbling upon this hidden treasure trove of vehicles.