The movie was filmed in the actual abandoned Chippewa Lake amusement park. At the start of principal photography, the park had been abandoned for 30 years, and had recently been sold. The new owners allowed to let the crew shoot the movie there for free.
All of the people seen walking by the ferris wheel at the end of the movie were local residents of Chippewa and the surrounding towns. Hundreds of people showed up to be in the scene, where shooting was delayed for a few hours due to rain. When the rain stopped, everyone came back.
The stories about the various rides in the park and the Carny's car are all based on real urban legends surrounding Chippewa Lake Park.
When Kristy hands the Carny a $5 bill, he responds, "What the hell is that, cartoon money?" James then says that he has some "real money" and hands him a few singles. The design of most American currency was drastically overhauled at the start of the 21st century (during the era when the park would have been closed), but the look of the $1 bill never changed.
The Carny is played by character actor Joe Unger. His father in real life, was a Carny, and may have actually worked in Chippewa Lake Park when it was open.