When Kramer's karate classmate comes up to Jerry's apartment to get Kramer, the kid's mother honks her car horn to get them to hurry up. The horn can be heard very clearly. This is impossible since Jerry's apartment is 5 stories up and the windows are closed. In addition, it makes no sense that just her horn is heard in NYC; notorious for multiple cars honking their horns.
The first time we see the exterior of Monk's restaurant it is clear that the letter before the apostrophe is not a K. Other shots are careful to crop out everything before the apostrophe so as not to reveal the real premises used for exterior shots, Tom's Restaurant on W112th and Broadway.
Jerry (Jerry Seinfeld) misquotes the movie Star Trek II: The Wrath of Khan (1982) in this episode. The actual quote was "He's not dead, not as long as we remember him." not " as long as we find a way to remember" as Jerry says.