Grandpa's Sister / Synchronized Swimming - S4-E12
Continuity mistake: Synchronized Swimming: During the swimming tournament, the boys take off their jackets beside the pool. When the boys jump in the pool, they disappear. (00:20:55)
Grandpa's Sister / Synchronized Swimming - S4-E12
Continuity mistake: Synchronized Swimming: When the boys take off their jackets during the swimming tournament, Gerald's boots change from brown to black mid-shot, and when the camera pans over to Stinky, his boots are also black instead of brown. (00:20:45)
Grandpa's Sister / Synchronized Swimming - S4-E12
Continuity mistake: Synchronized Swimming: When the boys take off their jackets during the swimming tournament, Sid is missing from the group. When the boys dive into the pool, he returns. (00:20:46)
Grandpa's Sister / Synchronized Swimming - S4-E12
Continuity mistake: Synchronized Swimming: In the pool scene at the beginning, we see a close-up shot of Connie and Maria. In the next shot, they are nowhere to be found. The three kids surrounding the pool in the beginning also disappear. (This happens because the opening shots are reused from the episode "Sixth Grade Girls.") (00:12:01)
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.