Uncle Lewis and Aunt Bethany Literally Made the Set Shake

The arrival of Uncle Lewis and Aunt Bethany wasn't just a stressful time for Clark Griswold, but apparently the Earth's crust as well. While filming the scene where Lewis and Bethany arrive at the Griswold home, you may notice a small shaking of the camera as they walk through the front door.

This was the result of a minor earthquake during production that wasn't even really noticed until after the scene had already been filmed. It would be hard to notice without prior knowledge there was a small earthquake during that time.

The Opening Credits Were a Rarity

During an age when films were trying to use the latest technology around, animation seemed like it was on its way out, especially animated intros. This is what made the intro to Christmas Vacation such a rarity — especially considering that the film was live-action.

Christmas Vacation was only one of three movies in 1989 to use animated opening credits with the others being Honey, I Shrunk the Kids and Troop Beverly Hills. While back then it may have seemed underwhelming, today, it's part of what makes the film unique.