Meg did not have any speaking lines in this episode.
Stewie's homosexuality is suggested twice in this episode. After flying past the statue of David he comes back for a second look at the penis, and when he wakes up in present-day Quahog he tells Brian to kiss him to wake him up.
When Stewie is awakened by Bertram in the middle of the night, he is shown to have been sleeping in his daytime clothes, not pajamas or a baby sleeper.
In the uncensored versions of the episode, Stewie mentions that he got to stay up late until 7:30pm to watch Phineas and Ferb. Phineas and Ferb was created by former Family Guy director Dan Povenmire.
The scenes in Italy skip between Florence and Venice as the DVD commentary explains that Seth wanted the air battle to cover all of Italy. Bertram firing rockets and striking the Coliseum in Rome are part of the animatic but were dropped for time.
Astrophysicist Neil DeGrasse Tyson, who would later host the Seth MacFarlane-produced revival of Cosmos, is credited as the Scientific Consultant for this episode.