These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
YMMV: Pee-wee's Big Adventure
Big Lipped Alligator Moment: Large Marge's face turning into a ghoulish image. This is because as she had died in a car crash and it was her ghost who picked up Pee Wee.
It's a Shout Out to the old song "Phantom 309", which features a ghostly trucker named Big Joe.
Special Effect Failure: In the pan-and-scan version of the film, you can clearly see Pee-wee's chain feeding up through the bottom of his bike's saddlebag. This is a common problem with pan-and-scan version of videos, which display more space along the top and bottom of the frame than is visible through a projector.
The increasingly insane road signs are obviously being rolled past the camera on a track.
When the convertible is falling, the lack of wind in the closeups makes the fact that Mickey and Pee Wee are sitting in a tilted but stationary car rather obvious.
The car might fall under Narm Charm or Stylistic Suck since it fits with some of the other, obviously intentional stylistic choices in the movie.