They don't theme the parking lots, though. They put some names on them to help people find their cars, but there's no actual theming.
The Magic Kingdom entrance is designed specifically to separate the lot from the theme park, and Animal Kingdom does this as well to a lesser extent. I guess you could argue DHS and EPCOT also do, but not at the same level.
The promotional material at DHS lot carefully in the art deco style as well as the themed/inspired Skyliner station point to the balance of that. It is not a show as in the immersion of a theme park, but it is the start of an attitude to whisk the guest away.
This is right down to how EPCOT Parking was designed so you are walking to and under Spaceship Earth.
Its kind of semantics as words are a part of the "show' of Disney. nomenclature such as Cast Member, Courtesy Tram etc...
So the characters and names of the lots are carefully chosen too. And this has taken a decline for many.