The widescreen version is actually the regular full screen version but with the top and bottom blacked out. This is proven in the scene were the teenagers are watching
Attack of the Killer Tomatoes! (1978) at the theater. For the scene were a woman with a shopping cart is running from an oversized tomato, the board with rollers the tomato is sitting on is cut off. As is the shot of Elvira's Elvis T-shirt when she suddenly sits-up from her nightmare. This is because the movie was shot in full screen, and matted for theaters. The extra space in the full screen version is dead space that was never meant to be seen.
