When Alan says, "Jake flipped Miss Pasternak off", Miss Pasternak says, "We don't end our sentences with prepositions." The writers (who are awesome script writers) are missing the point. In that sentence, the word "off" is not a preposition. It is part of the phrasal verb "flip off". An example of ending a sentence in a preposition would be, "She's the teacher Charlie slept with." And the rule against this is antiquated.
In the hallway scene of Jake's school, a sign in the background says "intermural" instead of "intramural".