Michelle is also the name of the Ghost of Christmas Past, who helps Stan to make it a perfect Christmas in "The Best Christmas Story Never". The commentary mentions they intended to keep the same character but ran into negotiation trouble with Lisa Kudrow who performed the original Michelle.
Stan and Francine's Safari trip is one of the few vacations that the Smiths did not go into the goo chambers. This also shows that Hayley was born in Africa naturally, but in "Star Trek", Francine revealed to Steve that Hayley was born via Caesarian section and Steve was born naturally.
When Stan finds God's office, it has double doors. When Stan opens the door, only one door is shown from the inside.
Roger believes Christmas spirit is like the Quickening from Highlander.
Michelle claims that she once got into an argument with God about abortion.