Continuity mistake: In the end of the episode whilst the families are eating lunch at the picnic table there is a lot of plates of food and glasses on the table. Towards the end of the scene Brian says "I guess some mysteries are better left unsolved", there is a wide shot after he says this and every plate and glass from the table has disappeared. (00:21:25)
Continuity mistake: When Spooner St. is announced as the parade's winner, Lois and Loretta hug. In the next shot, they are both waving their hands in the air.
Continuity mistake: At the end of the episode everyone is having a picnic. Joe says what the heck happened to that trophy and everyone's plates disappear. The table is completely empty.
Continuity mistake: When the guys are arguing over the trophy Quagmires teeth disappear for 10 seconds. His mouth is all black then they reappear.
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