Partial Terms of Endearment - S8-E21
Continuity mistake: In this episode, Lois is shown to have dated Naomi during college. But in the episode "Meet The Quagmires", it was established that Lois and Peter were already dating when Lois was eighteen. She accepted Peter's marriage proposal at that age. She would have been engaged and possibly married during college, not dating other people.
Road to the Multiverse - S8-E1
Continuity mistake: At the fair, Stewie's genetically perfect pig has a red collar. But when we see them in Stewie's room, the pig's collar is black.
Road to the Multiverse - S8-E1
Other mistake: In every universe - except for the double-headed universe - Brian and Stewie travel to, they (seem to) replace the version of themselves that universe already has of them, but then in the Dog universe they have a separate version of themselves that they continuously interact with.
Something, Something, Something, Dark Side - S8-E20
Continuity mistake: When Han lands the Millennium Falcon in the "handicapped" crater on the asteroid, the handicapped parking logo disappears from the ground. (00:22:45)
Chosen answer: It's a real song called "Elvira". Originally by Dallas Fraizer in '66, however, this version seems to be the Oak Ridge Boys cover version. However, the mega lesbians skip the verse and just sing the chorus after the opening line.
Bishop73