Goofs

Mackey's police car switches between 1981-1985 Chevrolet Impala and 1986 Chevrolet Caprice.

During the festival Ipswich celebrated, there was a Red Moon. No Red Moons occurred in the U.S. during the summer of 1984.

The scene where they tip over the trash cans. Davey looks at Mackey's house from his window and the cans are no longer there.

Dusty Dewitt (the kid on the milk carton) is referred to as a "Ginger" (or red head) even though his photo is in black and white. Also his hair does not appear to be red in the scene where Davey sees Dusty with Mackey.

Mackeys Jeep Cherokee is a 1990s model. The rims on it were not around in 1984.

Officer Mackey's name is written as "Hackey" on the refrigerator.

Mackey is outed as the killer and is on the run yet somehow is able to kidnap Curtis and Dale using his police cruiser.

Mackey's personal vehicle, Jeep Cherokee, has daytime running lamps (DRL), which wasn't even used in the United States until 1991 when General Motors started to implement DRL system.

Cheerleader skirts in the bowling alley scene are a-line, a style not available till around 2000.

A maroon-coloured Chevrolet Caprice parked on the street is a 1987-1990 model. Caprice receives the composite headlamps for 1987 model year.

The centre high mount stop lamp (CHMSL) is visible in the police car where Davey and Dale attempt to escape from. The CHMSL isn't mandated until 1986 model year with CHMSL being optional fitment in 1985.

Although they were invented in the 1960s, dry-erase boards weren't widely used until the 1990s, and even then they were generally used in offices and classrooms. Having a small whiteboard in the home in the mid-1980s - one that attaches magnetically to the fridge, no less! - would be unheard of.