Timberly Loves Arnold / Eugene, Eugene! - S5-E22
Continuity mistake: Timberly Loves Arnold: When Gerald says, "I could go for some Arnold lemonade," and Arnold pulls him in the alleyway, there is a building with a sign with the word "shoe" on it, written in red. In the next shot, it changes to yellow. (00:04:07)
Timberly Loves Arnold / Eugene, Eugene! - S5-E22
Continuity mistake: Timberly Loves Arnold: Throughout the scene where Arnold, Lila and Timberly are at the lemonade stand, Lila is wearing her gold button on her shirt. When Timberly asks Lila if she wants to come to the baseball game, as Lila says, "I'm sure that I'd love to," she moves her hands, and for a brief moment, you can see that she is not wearing her gold button. (00:05:46)
Timberly Loves Arnold / Eugene, Eugene! - S5-E22
Continuity mistake: Timberly Loves Arnold: When Arnold, Lila, and Timberly are in the field together after the baseball game, Lila helps Arnold up and looks at her watch, which she wasn't wearing previously. Then, when Lila starts walking Timberly home, her watch has vanished from her wrist. (00:06:35)
Ghost Bride/Gearold VS Jameo - S5-E25
Continuity mistake: In the scene where they are running from the second ghost bride, they go into a crypt and close the doors. One of the kids puts a shovel through the handles to keep it shut. In the next shot, it's gone. In the shot after that it's back.
Answer: The show is based in present day times. Plus most cars aren't old fashtioned, I recall seeing a limo and not to mention a cherry picker, etc.