Freeze Frame / Phoebe Cheats - S2-E8
Continuity mistake: Phoebe Cheats: In Phoebe's room, there is a green mat on her desk, but it is missing in all the wide shots from behind Phoebe as she sits at her desk. (00:12:50)
Freeze Frame / Phoebe Cheats - S2-E8
Continuity mistake: Phoebe Cheats: After Phoebe reads the poem from her book, it then cuts to a wide shot from behind her; only she is not holding the book anymore; she is writing on her paper with her pencil. In the next shot, she is holding the book again. (00:14:00)
Freeze Frame / Phoebe Cheats - S2-E8
Continuity mistake: Phoebe Cheats: After Phoebe reads the poem from her book, she sets the book back against the lamp, and there is a blue book under the poem book. In the next shot, the blue book disappears. The location of the lamp and poem book also changes. (00:14:05)
Freeze Frame / Phoebe Cheats - S2-E8
Continuity mistake: Phoebe Cheats: When we first see Phoebe writing her poem in her room, the red book beside her repeatedly changes direction depending on the shot. (00:12:49)
Arnold Visits Arnie / Chocolate Boy - S5-E12
Audio problem: Arnold Visits Arnie: When Arnold, Arnie, and Lulu leave Arnie's house, the shot fades to them at the swimming hole. Lulu then says, "So," but her mouth does not move. (00:04:39)
Sid the Vampire Slayer / Big Sis - S5-E3
Audio problem: Sid the Vampire Slayer: When the lunch lady asks Stinky, "Garlic bread, Stinky?" her mouth does not move. (00:03:35)
Grandpa's Birthday / Road Trip - S3-E7
Audio problem: Road Trip: When Miriam points out the Wheeler Inn and Big Guy Restaurant while driving, as Helga says, "I really don't think," her mouth does not move. (00:14:56)
Hall Monitor / Harold's Bar Mitzvah - S2-E15
Other mistake: Hall Monitor: After all the kids run into Phoebe, when Sid runs past her and her hat comes off, we can see that the hair above her scrunchie is yellow instead of black as it should be. (00:03:44)
Abner Come Home / The Sewer King - S1-E16
Other mistake: Abner Come Home: When Arnold wakes up and starts looking for Abner, as he walks into the kitchen, his hair clips through the doorway. (00:04:14)
Abner Come Home / The Sewer King - S1-E16
Other mistake: Abner Come Home: In Abner's flashback, Grandpa shows him how to get in and out of the door. We see grass outside the door, but what we should actually see are the stairs that lead to the door, not grass. (00:03:08)
Continuity mistake: When Pea Pod Kid is taking Rhonda's marriage predictor test, Sid is walking down the stairs behind them. In the next shot, he disappears. (00:03:44)
Love and Cheese / Weighing Harold - S4-E7
Other mistake: Love and Cheese: When Arnold and Lila's boat is stuck at the edge of the waterfall, as Lila says, "Arnold, what will we do?" a piece of the boat next to Lila is incorrectly coloured like the background and the seat, so it looks like a hole in the boat. (00:10:14)
Hall Monitor / Harold's Bar Mitzvah - S2-E15
Other mistake: Hall Monitor: When Helga is deciding on the new hall monitor and it shows a shot facing the crowd, many kids sitting in the back are faceless. (00:02:20)
Hall Monitor / Harold's Bar Mitzvah - S2-E15
Continuity mistake: Hall Monitor: In the cafeteria, when Gerald throws his detention slips on the floor, Phoebe gives him another slip. Phoebe is first behind the railing, but in the next shot, she is in front of the railing. In the following shot, she is behind the railing again. (00:08:26)
Hall Monitor / Harold's Bar Mitzvah - S2-E15
Other mistake: Hall Monitor: When Helga chooses Phoebe to be the new hall monitor, as Phoebe is walking to the stage, Iggy's hair is incorrectly coloured black instead of brown. (00:02:30)
Timberly Loves Arnold / Eugene, Eugene! - S5-E22
Continuity mistake: Eugene, Eugene!: The hat Lila wears with her Betty costume has a yellow crown with a green ribbon around it. However, when Arnold sings, "Nice Guys Finish Last," as he sings, "Take his money, grab his honey," the crown of her hat is entirely green. (00:17:00)
Timberly Loves Arnold / Eugene, Eugene! - S5-E22
Other mistake: Eugene, Eugene!: When the kids sing "Sunny Side Up" at the end, as they sing, "Who cares if the day is foggy and gray?", the crown of Lila's hat disappears for one frame. (00:22:46)
Runaway Float / Partners - S2-E20
Continuity mistake: Runaway Float: The big beeper float constantly changes appearance during the parade. Some examples: The sign saying "Let's Go Downtown" on the front changes to "Let' Go Downtown" in one shot. The sign saying "Let's Go Downtown" on the back is missing in one shot. The orange base is sometimes blue. The blue city design around the base sometimes isn't there, and it even changes colour. (00:08:17)
Runaway Float / Partners - S2-E20
Other mistake: Runaway Float: When Bob asks the kids who wants to ride on the float, Arnold says to them it's great the way it is. In one shot, Iggy's hair is incorrectly coloured black instead of brown. (00:05:52)
Runaway Float / Partners - S2-E20
Continuity mistake: Runaway Float: When Arnold reaches the parade float on the bike, Iggy's shirt is incorrectly coloured green instead of purple. It's also green when the float rides past Mayor Dixie. (00:09:45)
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.