The guys take Leonard on a road trip to Mexico for his bachelor party. Penny, Bernadette, and Amy have a "girls night." Amy wants to make a change. Penny calls her dad to tell him the news about her elopement. He shares some upsetting news.
- Abusive Parents: Amy's mother locked her in "the sin closet" when she rebelled. It's Played for Laughs.
- The Alcoholic: Penny's brother just got his tenth "one month sober" chip.(Your mom) can make a necklace out of them.
- The Bus Came Back: Penny's father Wyatt returns in this episode after his first appearance in Season 4.
- Epic Fail: In trying to replace a flat tire, the guys end up burning down the van.
- For Science!: A mild example, as the guys use various physics principles to try and loosen the lug nuts.
- Gilligan Cut: Sheldon asks how the guys are going to get him to go along in their trip to Mexico. Cut to Sheldon tied up and blindfolded as the others load him into the van.
- Percussive Maintenance: In this case, Percussive Shock.
- Poisonous Captive: Sheldon really doesn't want to go to Mexico.
- The Precious, Precious Car: Howard borrowed Richard Feynman's old college van for the ride to Mexico. It ends up burning down.
- Stag Party: The guys plan to give Leonard a belated bachelor party. It gets sidetracked by a flat tire that they try to replace and leads to the van burning down.