'''Airdate''': November 2nd, 2008.
Peter is given an unlimited gas coupon for a year by Carl the convenience store clerk and Lois decides to use the card for a family road trip, but they accidentally leave Stewie behind and Stewie must learn to fend for himself until his family either comes back from the vacation or return after realizing they left him at home.
!!Tropes present in "Baby Not On Board" include (([[YMMV/FamilyGuyS7E4BabyNotOnBoard YMMV Goes here]]):
* EasilyForgiven: Peter's rebuttal to Lois's TheReasonYouSuckSpeech manages to make Lois feel bad.
* KarmaHoudini: To go along with the above mentioned EasilyForgiven, Peter once again suffers no consequence for literally almost getting his family killed due to his sheer stupidity and lack of focus. What makes this one especially bad is the fact that he probably wasnt even really paying attention to Lois calling him out and just felt like quoting ''Film/PlanesTrainsAndAutomobiles''.
* TheReasonYouSuckSpeech: Lois manages to dish a harsh one out to Peter, actually stating that a monkey would be comparable to him. Peter conjures up a rebuttal quickly.
-->'''Lois:''' Here's a little tip, if your instincts tells you to do something, '''''don't do it'''''. If your instincts tells you not to do something, '''''it's probably the right thing to do!'''''
** ''Film/HomeAlone'': The subplot of Stewie being left behind and setting traps to capture whom he thinks are burglars (they're actually Quagmire and Cleveland) in his basement.
** ''Film/PlanesTrainsAndAutomobiles'': Peter's speech and the fact that he brought shower curtain rings.
--> '''Chris''': [[LampshadeHanging Haha, movie references!]]
** The cutaway with [[Franchise/TheMuppets Fozzie Bear]] performing for Arabs parodies the "fat sailor" joke from ''TheMuppetMovie''.
* TookALevelInDumbass: Even by Peter's standards, he's a complete dolt in this one, and Lois lets him know this.