The Griswolds finally make it to Walley World, only to find it closed for cleaning and repair. This causes Clark to go temporarily insane. After purchasing a BB gun, Clark holds up the security guard and forces him to allow his family to go on the rides. Eventually a SWAT team turns up and the family are arrested but Clark speaks to Roy Walley himself, reminding him of his own hellish vacation roadtrips. Walley decides to drop the charges, and allows the family (and SWAT team) to remain in the park as his guests.
The end credits show various snapshots from the vacation. The final shot shows that, unsurprisingly, the Griswolds decided to fly home.
Hazax of Rodmore