In several scenes, Boogie is seen driving his car with the column shift transmission in "Park".
In the first diner scene with the roast beef sandwich, Shrevie takes the sandwich from Eddie, but in the next camera cut, Eddie has the sandwich back and is still eating it.
Boog's '57 Chevy keeps changing from a 6 cylinder to a V-8 throughout the movie. In 1957, a V-8 was identified by a V on the hood, just under the "Chevrolet" script; same on the trunk lid. In the movie, some scenes show just the Chevrolet script on the hood, and no V, which would indicate a 6 cylinder. Others scenes show nothing on the hood, indicating it was customized. Some scenes show the trunk with no V and some with both the V and the script.
When Boogie and Tim are driving on the country road (following the girl on the horse), Tim's window is rolled up/down between shots.
The grip Mrs. Simmons has on the knife when she is chasing Eddie around the kitchen table varies.
This movie is set in 1959, and it is stated they are watching a Pittsburgh Steelers/Baltimore Colts game. They didn't play each other that year.
When discussing marriage outside the diner, Eddie tells Shrevie that he and Elyse will be vacationing in Cuba, which had already been taken over by Castro on 1 January 1959. By New Years Day 1960, a honeymoon in Cuba would have been considered out of the question.
Baltimore and Ohio ended rail service from NY and Philadelphia to Camden Terminal in 1958, so Billy would not have arrived at that station.
When Boogie is driving in the country, the road has two yellow stripes on it and when there are "passing" stripes, they are yellow and not white, as they would have been in that period of time.
In the wedding scene at the end, which is New Year's eve 1959-60, the bass player in the band is playing a black Fender Jazz Bass. The Fender Jazz Bass was not produced until later in 1960, and was not available in the black color shown in the movie and formally named the "Jazz Bass" until 1962.
Story takes place in 1959. The wedding band bass player is using a Fender Jazz Bass. They first hit the market in 1960, and the one he is playing is a 1970s model.
A man wearing glasses and holding a camera is reflected in Tim's window when Boogie and Tim are driving on the country road (following the girl on the horse).